Suzuki GS GSX250, 400 & 450 Twins 249cc-399cc-448cc. '79-'85 (Haynes Manuals)

Citation preview

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wners

I

nua by Chris Rogers .... 'In an add,I,On,J' ·/liiDle. on UK GSX250 400 ez and uS G5 450 models by Pete Shoemark the

Models covered GS250T 249cc Introduced UI( ilnd US 198 0 Gs x2 S0E 249" Introduced UK only Januerv 1980 GS J(4 00E 399, I"\loduced UK onl~ August 1980 GSX4 0Q T 399(l!O

1& IOOH

400 &

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H448 S8 ~~l •

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Acknowledgements Our Ihanks are due to Fran R,dewood & Co Wells 50mers.el ..... ho supploed Ihe mach.ne featured ,n the photo graons th.pughout It", Manual S"PS~ ,,,,,I ,'VP" (!l'alh ,I ,nh"ll"It 10 any t'''e,,1 Pt'lrul a,1 Ihe ,,'SI,uc· t,,),,~ L.l v,'Il,(If'S I",!!!"" II w,1I norm.:lIlv bl' 9,v,ng oil " (;erl;lIn "mUU"1 ,)1 hyd'oql"n ",IS wh..-h I~ h'U"IV e , pIO~'"P AlwdVS (i,sCOrl ae,rI slowly 10 Ihe wale' and neve' the olhe, wav .ound PrOlecl dya,nst splashes bv weatlng rubber gloves and goggles

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MainS electflclty and electflcal eqUipment When USing an el~l"e POwe, 1001 Inspec t'on IIghl elC_ always ensure !ha l the apphance '5 correclly connecled 10 115 plug and thaI where necessary 1\ '5 properly earthed (g,ounded) Do nOI use such apphances 'n damp ,ondmons rJnd aga,n bewa.e of Creating a Spa,k or apply on5ula!10n '5 de fcel,ve Whe,e an electronic 'qn't,on on spllnne.s lind a sel 01 Allen keys (sockel w'enche5)

Check Ihe tv,e preSSUleS w,th a gauge Ihat '5 known to be accur"e

2 W eekly a . eve.y 300 mtle s 1500 km )

,

Tyre pressures

Retel 10 the pressure table on page 10 and check Ihe lyre o lt>d.U'y!'· 10 1>.. nbsf' ...... cOllet! loulon9 01 Ihe ~ent pipe

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'I'"''''

oil IlIvlll wieh ehll d'P5IiCk-;';;;id.;

•

'" ',,' final cI,,~e chaon lubflCl1l0n 's eSSl.'n l ,al

II ,f:QI.U,e6 .•• '",,,,,,,,,,,, ,,,, .esen/o" w 'lh SAE I OW engone 0.1

5

e

UPPER L LOWER LEVEL

Fill'll elr/ve cham lubricatiOTl

In (,,1'1 b~ {lI'''"¥ lallP ''I 1'01"" o"t' w,th J melal objet;! A 10051' ~1)Qke .~ ,demlf,able bv lhl' low rilich n.o,~e emllied whpn st.u("1.. 1/ any on .. spoke neMs conStd"'able IIgt"t-n",y ,t WIll be netessa,y to remove Ihe I"re .1nr1 "lrWr luhe ,n Of de, 10 hie r10wn Ihe p.otlllnlng spoke enn ThiS w,1I prevent II t.om chalmlJ lh'o"'gh Ihe rom band and 1"'H~lI1g Ihe lime, I",be

CAUTION MISE EN GARDE 8illt.!y Ballerle

2

Cast allov wheel inspec t ion

On mach,nes f,ned W'lh casl alloy wheelS ca.ry 0",1 a (01,('1",1 , lever maf~S Ensurl' Ihat Ihe hancllebars are ,n th" ['pn1l,ll [>OSITIon ""'hpn a Il'v .. 1 'I'an,ng ,s ta~l'n ann also when Ih£> Colt> anck Ihl' honl b.a~e maSler -~linde. hOSfts and caloper ",n.t§ jor s'l1"s of leakag" P.w panLo,lar anl'""on 10 Ih(' C:Ond,tlon of Ihe hoses wh,~h shoulr1 Ill' 'enewl'n without q"e~IIon If Ihe'l' die slgn~ oj c'oId,iny splo\llng o. olhe. e~Il'''o' r1amag('

SAE JII03 Dor3orDOT4

C"." ShOlllO be T~ken Ihat " spe~lf'eo fluid,s used An ,,,celf'f'l'les lined wl!h the C:onvf'nt,onal

\~ne

01 wore

Routine ma intenance

14

' -____ "',..,

~ .t>~

Secure !!ltch adluste. bol l wl1" Its locknu t

Fou, monthlv or every 2000 mIles 13000 km t Complete Ihl'! las~s I,Sled under the weeklv and monthly service head,n9S lind then carry 01,11 the lollowing

,

Final drive chain fubrication

Lub'oc1l1'On 01 the teBt cha,n should be camed 01,1\ al short '011""1115 ;is descflbed on SectIOn 5 01 the Weeklv o. 300 mile 1500 ~ml m"menance SChedule On machones I,ued wllh 11 non-Slandard cha.n u5.ng a spnng JOlmng hn~ mOle Iho.ough lub,,~ahon should be carr,ed OUI w.,h the chaon off the mach,ne The 0"9.nal cha.n has no SJlflng I,"~ and Iherelo.e 5wln9,ng arm 'l'mOllal must liI~e place befo.e the chaon can be remO\led In Ihls t!I~ .. II .5 suggested Ihal Ihe cha,n be cleaned Ihoroughl'o' wh,ls' 51,11 on 1)(I5+"on uSIng a pfOPf,e l arv degrease. such as ·Gun" or J, ze' and Ihenlubrocated us,ng graph, ted g'ease f,om an al'IO'i01 can Whe,,, a cha,n ha~,,'g a sprong Ionk '5 used separale the eh,,,n bv remo~ing the 5pung lonk and run \I o ff the 5proc~elS /I an old cha,n '5 a~a,lable interconneCI the old and new cha,n. ~fore the new cha,n.s run off the sprocke ts In t h,s wa~ the old cha'n can be pulled into place on the sprockels and then used to pull the ,egreased chain onto place w,th ease Clean thl' cha'n thoroughly on a para Hon ba th lind then fonally Wllh Pl' t.ol The pet.ol will wash Ihe pa.affin ou t 01 the links and rolte.s wh,ch will then dry more Quicklv Rumembe. Ihat petrol '5 h'ghlV fla mmable and care should be lake n to :wo,d accidents A llow the chaon to d.v and then ,mmerse it in a molten lub"cant Such as Llnklvle o. Cha'nguald These lubtlcanl5 must be used hot and Will achieve beller penetra l ion of I he links and rOliefS They afe less I'kel y to De Ih,own off bv CE~n t "fugal force when the cha.n IS in mo t ion Rel,t the newlv g.eased chain onto the sprocket. f ittong Ihe spI'ng link Th,s 15 accomphshed most easilv when the free ends o f Ihe cha,n are pushed Into mesh on the .ear wheel Sproeket The spring !res Ire between 32 ° F Ind Clllrol Grind Pri .. 1r:Jd gearbo_ mainshalt assemblies. In time it is possible tha t anyone of these seals will wear or harden wi t h age thus allowing oil to l ind its way past. Although t he seals themselves are relat ively ine _pensive. a considerable amount 01 dismantling wOfk is necessary should one fa i l i n service. For this reason i\ Is advisable to renew all oil seals in !he even! of a full engine overhaul. In any case. a seal which look s remo tely suspect should be renewed.

20 Elt amination and renovat ion : cyl inder block 1 The usual indication of badly worn cyl inder bores and pistons is excessive smoking from the exhaus ts. high crankcase compression which causes oil leaks. ilnd piston slilp. a metallic ratt le that occurs when the re is little or no load on the engine. I! the top of the cylinder bore is e_amined carefully. it w ill be foun'd that there is a ridge ilt the front and bilck. the depth o f which wilt indicate the amoun t of wear which has I8ken place. This ridge marks t he limit of travel 01 the top piston ring. 2 Since there is a difference in cylinder weilr in different directions. side to side and back to frOnl measurements should be made. Take measurements al t hree different points down the leng t h of the cylinder bore. st arting 8t a point jusl below t he wear ridge and following t his with measu rements hal! way down the bore and at a point just above the lower edge 01 the bore. II any 01 these measurements exceed the service limit given in the Specifications Section of this Chapter. the cylinder must be rebored and fitted wi t h iln oversi ze pi ston. Never rebore one cylinder withou t reboring the other to t he same sire as t his will only result in the balance of the engine being dist urbed w ith the resultant increase in vibration and wear ra te. 3 Oversize pis tons are available in twO oversizes of 0 .5 mm (0.020 in) and 1.0 mm (0.040 in). 4 Check that the surface of t he cylinder bore is free from score marks or o t her damage tha t may have resulted from an earlier engine seizu re or a displaced gudgeon pi n. A rebore will be neceSSilry to remove tiny deep scores. irrespective o f the amount o f bore wear thilt has taken place. otherwise a compression leak will occur. 5 Clean Ihe cylinder block to cyl inder head mating surface and check it for distortion with it straight -edge and a sel of feeler gauges. The straight -edge should be laid diagonally across the ma t ing surface from cornar to cornar and any clearance between ils lower edge ilnd the mating surface checked with the gauges. Repeat t he procedure wi t h the straigh t-edge l aid between the opposite corners and t hen at several positions in between the l our corners. If the largeSt clearance found e_ceeds 0 . 10 mm (0.004 info Suzuki recommend t hat the cylindel block be replaced with a new item It is worth no ting however. tha t if the amoun t o f dis tortion lound is only slightly g.ea ter than t he limit given. it could well be WOrth seeking Ihe ildvice of a competen t mo torcycle engineer who can advise on whethe r skimming the ma ting surface lIa t is possible without the subsequent risk of t he pistons coming in to contact with the valve heads once the engine is reilssembted and sl art ed. 6 Finally. make su re Ihe e_ternal cooling fins o f the cylinder block are nOI clogged with oil or rOad din which will p revent Ihe free flow of air and cause the engine to overhea t.

21 Examination and ren ovation : piatons and p i lton ring, 1

A tten t ion to Ihe pistons and pis tOll rings can be overlooked if a rebore is necessary. since new componen ts will be fitted . 2 I! a rebore is not necessary. e_amine each piston carefully.

49

Reject pis tons that are scored or badly discoloured ilS the result o f e_haus t gases by-passing the rings. 3 Remove ilil carbon Irom the piston crowns . using a blunt sc raper. which will not damage the surface 01 the piston. A scraper made from soft aluminium illloy or hardwood is ideal: never use a hard metill scraper wit h sharp edges as this will almos t ce rt ainly gouge the alloy surface of the piston. Clean away carbon deposits Irom the valve cutilways and finish off wit h metal polish so that a smoot h. shining surface is achieved. Carbon will rlO t adhere so readi ly to a polished surface . 4 Small high spoots on the back and f ront areas 01 the piston can be carefully eased back with a line swiss file. Dipping the file in methylilted spir its or rubb ing its teet h with chal k will prevent the file clogging and evenl ually scoring the piston. Only very small Quantities of materiill should be removed . and never enough to interfere with the correc t tolerances. Neve. use emery paper or cloth 10 clean t he piston skirt: the fine particles of emery are inclined to embed themselves in the soft aluminium and consequently accelera te the rate o f wea r between bore and piston. 5 Measure the outside diametel of the pi510n about 15 mm (0 .6 in) up hom the skirt at right angles to the line 01 the gudgeon pin. To determine the piston/cylinder barrel Clearance. sub tract the ma ~ imum piston measurement from the minimum bore measuremen t If Ihe clearance exceeds the service limit given in the SpecifiCiltions. the piston should ideally be renewed (given thilt the cylinder bore is within limits f This however. is seeking perfection. and an additional clearilnce of perhaps 0.025 mm 10.001 in) will not reduce engine performance dramaliCillly 6 ReIer to t he figures given in the Specifica tions Section of this Chapter and check Ihat the gudgeon pin bosses are not worn beyond t he service limit or t he circlip grooves damaged in any way. Check also that the ring grooves are not enlarged and thaI the ring to groove clearances for t he top and second rings do nOI exceed the limits given.

Fig . 1 . 10 Method of removing and replacing pilton ring a 7 Piston ring wear can be measured by inserting the rings in the bore from the top and pushing them down w ith the base of the piston so that they ilre square wilh the bore and close to the bottom of the bore where the cylinder wear is leasl . Place a feeler gauge between the 'ing ends "the clearance exceeds the service limi t the flng should be renewed. The e_pander bend of the oil control ring canno t be measured In pract ice. if wear o f the two side .ails exceeds the Jimit. Ihe three components should be renewed It is advised thaI . provided new rings have not been fined recen t ly. a complele set of rings be fitted as a matter 01 course whenever the engine rs dismantled. This action will ensure maintenance of compreSSIon and performance If

Chapter 1 Engine. clutch and gearbox

50

new rings are to be fitted to cylinder bores which IiIfe in good

condition and do not require

iii

rebore . it is essential to have the

surface of the bores honed 'ightly. This operation is known as

ghuebusting and as the nlimB suggests. il removes the mirror smooth surface which has been produced by the previous innumerable up and down strokes of the piston and rings. If the glalB is not removed . the new rings will glide over the surface. making the running -i n proc.:ess unnecessarily protracted. Note that new rings should not be fitted to iii part-worn cvlinder bore. as lhe resulting wear ridge may break Ihe top ring. particula rly at high engine speeds. The resulting debris could have very e ~ pen5iye

resulls.

B Check that there is no build up of carbon either in the ring grooves O f the inner surfaces of the rings, Any carbon depOsits should be carefully scraped away. A short length of o ld piston ring filled with a handle and sharpened at one end to a chisel pOint is ideal for scraping ou t encrust ed piston ring grooves. 9 Oversize top and second pis l on rings are stamped with a number on their upper edge adjacenl 10 the end gap. The number 50 denotes an oversi ze ring of 0.5 mm whereas the number 100 denotes an oversize ring of 1.0 mm. Oversize oil ring spacers are identified by the following colour corles.

Blue denOles 0 ,5 mm oversize Yellow denotes 7.0 mm oversize Red denotes /I slandlJrd sized splJcer The oil ring side rail oversi,es are determined by measurement across the ou t side diame ter.

2 1.7 M easu re pis ton ring wear as shown

22 e Jte m in . t ion and ren ova t ion : c yl inder h eed an d va lv . . 1 It is considered good practice to remove all carbon depOsits from Ihe combustion ch ambers before removing the valves lor inspection and grinding -in. Use a blunt ended chisel or scraper so Ihat the surfilces are not damaged. Finish olf with a melal pOlish t o achieve It smooth. shining surface. If a mirror finish is required . a high speed lelt mop and pOlishing soap may be used, A chUCk attached to a fluible drive will facilitate the pOl ishing operal ion. 2 Obtain eight marked containers so that the appropriate valve compOnents can be kept separate once removed . A valve spring compression tool mUSI be used 10 compress each sel of valve springs in IUrn. Ihereby allowing the spli t collets to be Ireed Irom Ihe valve stem and the spring le t aining plata. the springs, the spring seal and the oil seal to be removed from the cylinder head along. with the valve itsell . As each valve is removed , check Ih81 it will pass through Ihe guide bore without

resistance. After high mileages have been covered it is pOssible that the collet groove will have spreild and if this increilsed diameter is pulled through the guide bore, it will enlarge it. If any resistilnce is encountered. relieve the high spots with fine abrasive paper un t il the valve can be removed easily. Mark each valve so that it can be refitted in the correct combustion chamber. There is no danger 01 inadverten tly replacing an inlel valve in an e~haust pOsition. or vice-versa . as the valve heads are of differen t sizes. 00 not mark the valves by centre punching them on the valve head. This method is not recommended on valves. or any other highly stressed compOnents. as it will produce high stress pOints ilnd mily lead to early failure. r.e -on labels. suitably inscribed. or a spirit -based marker. are ideal for the purpose. 3 Using a micrometer. measure the diameter of the valve stem at various pOints along its leng th. II anyone of the measurements obtained is less than the seNice limit given in the Specifications Section of th is Chapter. the valve should be renewed . Check the amoun t of valve stem runout by suppOning the valve stem below two V -blocks and slowly rotating it whilst measuring the amount of runout with a dial gauge. Use a similar method to measure the amount 01 radial runout 01 the valve head and compare both sets of measurements obtained with the service limits given in the Specific ations. In either case . il these measurements are beyond limits. then the valve must be renewed , 4 The valve stem to guide clearance can be measured with the use 01 a dial gauge and a new valve. Place the valve into the guide and measure the mount 01 shake with the tip o f the gauge res ting Itg.inst the edge of the valve Stem head. Take two measurements. one at 90 ° to the other. and renew the valve guide il the amount of wear indicated is greater than the service limit given in the Specifications. 5 To remove an old valve guide. place the cylinder head in an oven and heat to it about 100° C !212 ° F). The old guide c.n now be tapped out from the cylinder side. The correct drift should be shou ldered with the smaller diameter the same size as the valve Stem and the larger diameter $lightly smilier than the 00 of the valve guide. If a suitable drift is nOI available a plain brass drift may be utilileo wilh great care. Even heating is essen t ial. if warpage of the cylinder head is to be avoided. Before removing old guides scrape away any carbon depOsits which have accumulated on the guide where it projects inlO the pOrt. Removal of carbon will ease guide movement and help prevent broaching o f the guide bore in Ihe cylinder head. If in doubt. seek the advice of a SUluki specialist. Note that each valve guide is filled with a metal locating ring wh ich muSI be discarded along with the guide. II is essential that the cylinder head is properly sUPpOrted during valve guide removal and that the rocker alms are not allowed to in terfere with the guide as it is tapped OUI of the casing. If necessary. remove each rocker arm and spindle by following the procedure given In Sec tion 23 01 Ihis Chapter. 6 Ream out the vatve guide holes in the cylinder head with an 11 .20 mm 10.4 4 in) reamer . clean away any swarfaOld lubricate the surface of each hole. F.ilure to keep the hole lubricaled during insertion of the guide may result in damage to the guid e or head. ensure the cylinder head is well sUppOrted on a clean flal work surface during insertion of the guides and is heated to the same heat as lor removal Fit a new lOCating ring to each new guide and drive each guide in to its hole until the locating ring abuts aga inst its rec ess in the cyl inder head. It should be noted that whereas the valve guidas removed from t he head and filled as o riginal equipment are of differing shapes. the replacement items are identical in shape. Following renewal of the guides. each valve seat may have to be re cu t to cen tre the seat w ith the guide uis Carry out the following check to detemine if this is necessary. 7 Before attempting to fit the valves in to their guides. leam out the guide bores with a 5 .50 mm 10 .216 in) reamer and clean away any metal particles from the bore surfaces and the head casting. Lightly lubricate each valve stem with oil and evenly coa t the valve seal w ith engineers Blue before fitting

Chapter 1 Engine. clutch and gearbox each valve info Its guode and pressmg It down onlO lIS seal lightly tap each valve onto ils Selll in (H'der 10 allow Ihe Engin.eers Blue 10 form a clear impression of Ihe sealing con ta c!. Remove each valve and e.amine Ihe impression left by the Engineers Blue on the valve lace. This impression muSI be con tinuous and its wid th within the limits 0.9 _ 1. 1 mm (0. 035 - 0 .04 3 in).1f this is not the case. recut the valve seat by using the following procedure. Note that the valve seats must also be recut il their surfaces have become so plll8(l that Ihe damage c annot be removed by using Ihe valve grindi ng procedure lisled in Ihe lollowing paragrapns. 8 In view o f the high COSI of Ihe CUlling lools required 10 recul the valve seats and of the e_pertise required. it is strongly suggested Ihal Ihis work be entrusted to a SUluki service agent or a compelenl motorcycle engineer. Never reson 10 e.cessive grinding because this will only pocket the valves in the head end lead to reduced engine efficiency. If. however. it is decided to allempt Ihis work at home. proceed as follo ws. 9 The valve seat CUlling set supplied by SUluki (1001 no 099 \ 6 -21 110) contains cutter attachments with 4 5 0 and 70 0 angles. Fillhe 4 5 ° anachmenl 10 Ihe 1001. Insert Ihe solid pilol InlO Ihe valve guide and rOla le i, slowly whilst pushing it inlo the guide until it seats correClly. Place Ihe 1001 inlO the pilo t and rOlale it once 10 CU I the valve seat Remove the 1001 and recheck Ihe valve seat contacI area w ilh Engineers 8lue. Repeat th is procedure until Ihe conta CI area I. seen 10 be conlinuous. If the COntact area is correc t bUI the valve Sflll is still pilled. repeat Ihe CUlling procedure until all signs of Dilling are removed. 1\ should be noted however. that if 100 much of Ihe valve seat i. cu t away. correc t valve adjustmenl wi ll be made impossible due to Ihe end 01 the valve stem becoming too close 10 the roc ker arm. lOOn completion 01 reCUlling the valve seat. inspec i its width to see if it is within the limits 0 .9 _ \ . 1 mm (0.035 - 0.043 In). Check also that Ihe seat contact area wilh Ihe vllive is in the position indicated by Ihe figure a ccompanying th is ted; ie in the ce ntre of the valve face . If Ihe con tact area is found to be 100 low. il may be raised and its width narrowed by carelully using the 75° CUller on Ihe tool. Th is may well result in the valve seat becoming 100 narrow. in whic h case lhe45 e cu tter will haV1! to be used to ret urn Ihe seat to its correc t width. Allerrnll ively. if the contact area is found to be tOO high. use the 4 5 ° CU ller to lower it Fig . 1 . 11 Velve s eet renovil lon

,

"w

W - seat width

Valve seat

~,

•

0

145

Seat reculling angles

5'

1 1 Once Ihe correCI valve seat wldlh and poSlllOn ,s aChIeved. ligh tly skun the sea t surfa ce WIth the 4 5 CUller In orde, to remove any burrs caused by the cumng procedure. The fino5hed seat surface $hould be matt m appeallnce and have a SmOOth fin iSh. Ih us providing the ideal surface for correCt bedding In 01 the valve once lhe engine is star1ed. It is nOI necessary to grind the valve in on completion 01 the reculli ng procedure 12 II it is lound that the valve seat does not need to be rec ut and is free 01 aU but the lig hlest pilling. Ihe n Ihe valv e may be reground in to Ihe seat by using the followong procedure. Valve gllnd lng is a relatIvely simple tasll. commence by smeallng a trace 01 lone valve grinding compound !carbof\Jndum paste ) on the valve seat and apply a sUCllon tool to the head 01 the valve OIl the valve stem and onsert the vatve ,n the guide so that the twO surfaces 10 be ground in make contaCt WIth one anolher Wilh a semi-rotary mOtIOn. grind m the valve head to the seill USIng a backwlud and lo rward action. Lilt the vatve occasionally so thai Ihe grinding compound is distrobuted evenly. Repeal the application un ti l an unbroken rong 01 ligh t grey milll finish is obtaoned on both valve and seal This denotes the grinding operation is now complete 8elore passing to the ne_1 valve. make sure thai all traces ollhe valve grinding compou nd have been removed from both the vatve and il5 seat and Ihat none has enllred the valve guide If thIS precaution is no t observed. rapid wear will lake place due 10 the hIghly abllsive nature of the Clrb(H'undum base No te that no maner which method of seating the valve is employed. the valve perophery must be checked to determine whether its thickness has WQfn beyond the service limit 01 05 mm (002 in ) II on comple tion of the valve seating p,ocess Ihis proves 10 be the case then the valve must be renewed 13 SUluki stale that refa cing o f the vllve stem end ;s P8'misslble. pro",ded the length belween Ihe stem end and Ihe upper lip 01 the valve colle t retDlning groove is nol reduced to less than 3 .60 mm W. 14 in ). in which case Ihe valve mUSI be renewed Upon refining a ref aced valve. lefer to the figure accompanying thisle_t whilst checking that the end of Ihe valve Slem protrudes above the upper laces of the valve colle ts 14 hamone the condition o f the valve cOUets and the g roove on the valve stem in which they seat " there is any sign of damage new parts should be filled Check tha t Ihe sprong retaonlng plate IS nol cracked If Ihe c ollets work loose or the plate spins wl'''lst the engme IS 'unning a valve could drop inlo the cyhnder .nd cause utensive damage , 5 Check Ihe Iree leng th o f each 01 the valve sprongs. The springs have reached Iheir serviceable liml' when Ihey have comp ressed 10 Ihe limi t readings given in Ihe SpeCifications SectIon o f IhlS Chapter 16 Clean the cylinde r head (10 cylinder blockl matIng su rfa ce and check it lo r distortIon with a straight· edge and a set 01 lee ler gauges The stralghl-edge should be laod dIagonally across the matIng surface Irom corner to corner and any clearance belween il5 lower edge and the matong surface cheC ked wnh Ihe gauges. Repeat Ihe procedure WIth Ihe stra.ght-edge laid belween tha OPposne corners and then aI several poSitions ;n belween Ihe four corners If Ihe large$! clearance found e_ceeds 0 10 mm (0004 in, 5UlUki rec ommend that Ihe cylinder head be replaced WIth a new Item II is worlh n01ing however. Ihat if Ihe amount of distortion found is only slightly grealer tha n the Iomi l gIven . •t could we ll be worth see king the advice of a compelent motorcycle engineer who can adviSe on whether skimming the mating su rfa ce fill is poSSIble wlthou' the subsequent fisk of the pistons coming in to contact WIth the villve heads once the engine is reassembled and started 17 II the cylinder head .s seen to be only Sllghlly warped the ma hng surface may be lapped on a surface plate or a sheel of plate glass. Place a sheet 01 4 00 or 600 g"l abraSIve paper on the surf.ce plate lay Ihe cyhnder head gasket -face OOwn. on the paper and genlly rub il with an osciUatong motIOn to 'emove any high spotS lIlt the head atlreQuent intervals to Inspee t Ihe prag/en 01 Ihe operation. and ta ke care to remove the

Chapter 1 Engine. clutch and gearbox

52

minimum amount of malerial necessary 10 reSlore III flat sealing

surface. It should be remembered thaI most cases of cylinder head warpage can be I.aced to unequal tensioning of the cvlinder head nuts and bolts by tightening them in incorrect sequence or by using incorrec t 0' unmeasured torque settings. 18 Finally, make sure that the e~lernal cooling l ins 01 the

cylinder head are not clogged wilh oil or road dirt whith will preven t the free flow of ai' and c!luse the engine to overhea t. 19 Reassemble the valve and valve springs by reversing the dismantling pnx:edure. Fit new oil seals 10 each valv8 guide and oil bol h t he valve stem and the valve guide with a molybdenum disulphicle based lubricant prior 10 reassemblv . Take special ca re 10 ensure the valve guide oil seal is not damaged when the valve is inserted. As a linal check after assemblv. give the end of each valve stem a light tap with a hammer, to make sure Ihe spl it colielS have localed correctlv. Note that each spring must be lilted with its close coil end nearest the cylinder head.

22 .2 Free Ihe split collets by compressing the valve springs

)

Fig . 1.12 Valva stem end relacing maa.uramant ,

Nor leu Ihlm 3 .60 mm (a. 14 inJ

stem

®

, ,, ...... Fig , 1.13 Correct f i ling of a refa ced valva .tam 1 2

J

Vil/ve relilining collets Groove in Vll/ve Slem VIJlve Slem

22 . ' 5 Measure the free lenglh 01 each valve spring

22.16 Check the cvlinder head lor distortion with e str.ightedge • nd feeler gauge

22 .19. Fit . new oil se.1 to each valve guide ...

22 .1gb ...before lubficlling .nd inserting the v.lve position) ...

..

22. 19d ...• n und.m.ged spring retaining pille ...

-

... and the split collets. which mutt be Ioclted correctly

Chapter 1 Eng ine. clutch and gearbox

54

23 Exam ination end renova tion : rocket .rms and spindlH 1

It is unlikely th el1 excessive wear will IXcur in either Ihe

locker a rms or Ihe rocke, spindles unless Ihe flow of oil has been impeded or the machine has covered 8 very high mileage. A clicking noise from the rocker area is the usual symptom Of wear in the l ocker gear, which should not be confused with II somewhat similar noise caused by excessive valve cr.erance. 2 If any shake is prese.,! and the rocker aIm if loose on its

shaft, eleessive wear belween Ihe two componen ts cen be suspected. Remove .ach locker spindle Irom its location within the head casting by removing Ihe plug and sealing washer from the cylinder h ...d . unscrewing the Spindle Slop boll and insertmg it into the Ihreaded end of Ihe spindle. The botl may then be used 10 withdraw the spindle. Pull the rocker arm IIssembly Irom ill lociltion lind inspect ill bellring lurfllce wilh thlll of Ihe spindle for signs 01 lack 01 lubriClllion. II such signs lire apparen!. Ihe laull in Ihe lubr ica tion syllem must be found and cu red belore progressing furlhe. J Meilsure Ihe overall diame ter of eac h rocker spindle and the bo. e diameter 01 each .ocker arm and com pa.e the measure ments obtained WIth those given in Ihe Specifications Seclion of th is Chapler. Renew each component as necessary.

4 Closely inspect each rocker IIrm for signs of aacking around ils bore ends lind betwe-en each adjusle. screw threaded eye. Ensure that the arm hilS been Ihoroughly cleaned in II degr8OlSiog agenl before il i5 inspec ted as Ih il will help to cI.rify any h.irline cracks Ihlll may be present in the casting surf.ce. 5 Inspect the surface of e.ch rocker arm where il mllkes con laC I wi lh the cilm lobe. II signs 01 cracking. scuffing or break through in the case hardened surface are in evidence. then Ihe arm must be renewed . Check Illso the thread of each adjust ing screw. Ihe threadS of the rocker 11m inlO which lhey fil and the thread of each locknut. II any of these threads snow ligns 01 damage. the component must be renewed . The hardened tip of each adjusting screw must Illso be in good condition. Finally. inspect Ihe rocker arm Springs for signs of fatigue or failure and renew each one as necessary. 6 Reassembly of the rocker componenlS is carried ou t by reversing Ihe dism.ntling procedure. Ensure Ihalthe hole drilled in the spindle to accommodate Ihe stop bolt 15 correctly IIligned with the hole in Ihe head clllling before refilling the bolt .nd tighlening it to the specified torque loading. Do not omit to fil the washer beneath Ihe head o f the SlOp bolt and lubricate the surface of the spIndle wllh clean engine oil prior to IOSlrling it in lO the cylinder head. Relit a new seilling wil5he, ben8iJlh the plug head before fiuing it in POSllion

23. b ..,," use Ihe Ipindle SlOp bol t .. head ...

2J.2 c ... ala means of withdr.wing the splndle from ilSloc'liofI

235 Inspeel the condition of lhe rocker IIrm con tact surface lind spring

Chapter 1 Engine. clutch and gearbox

4

8

l

55

6

J

Fig . 1.14 Camshafa and valve gear _ aU models

r6 ®-12 \f-n

15

~

17

0---1 6

(~

13 @r 17

14

'lr-16 ';>-; 13

- 21

1 2 3 4 5 6 7 8 9 10

II 12 '3 14 15 16 17 18 19 20

2I

,-- 20

-

9

22

Inlet Cllmshaft Inlel camshaft sprockat Lock washe, /Iale' models) Bolt - 4 0ff Elfhausl camshafr LOCllting pin - 2 off (Iala, models) Elfhausl valve - 4 off Elfhausr camshaft slYockel Lowa, spring seal - B off Inlel vlllve - 4 off Rocke, spindle SlOP boll - 4 off Washe, - 4 off Rocke, spindle - 4 off Rocke' arm spring - 4 off Rocke, arm - 4 off Ad;uSI;ng screw - 8 off Locknut Collet - 16 off Uppe, sp,ing sear - 8 o ff Inne, valve spring - 8 off Ouler valve s/Xing - 8 off a'lseal - 80ff

- 10

7 24 E~lIminlltion lind renovation : camsha ftl, bearing' and cam,haft drive Iprocketl

cams heft

1 The Cllmshllfls should be ellimined vis ....lly for weir, which will probably be most evident on the temps 01 each cam Ind where the cam oon to ... r chlnges sharply. A lso check the bellrit'lg surfaces for obvioul welt lind scoring. Cam tift can be checked bV meas... ring the height of the cam Irom the bo tt om of the base circle to the top of the lObe. If the measuremen t II lesl than the serviCe fimit given in the Specifications at the beginnit'lg of this Chapter. the openit'lg of the particular pair of valves will be red ... ced thus res ... ltit'lg in poor et'lgine performance, If anv one lobe , ...rface on either camshaft is found to be at fl ... lt, Ihat camshaft should be renewed in o«Ier 10 restore performence. 2 hch camshaft bears directlv on the cylinder head material and that of the belring caps. there beit'lg no aeparate belrings. Check the bearing surfaces for wear lind scoring . The cleara nce between the camsha ft beating Journals and the aluminium bearing lurfacas mlV be checked usit'lg piasttgagelprelS gl"'ge' mllerial in the same manner IS described for crankshaft bearit'lg clearance in Section 17 of thi5 Chapl er. II the clearance is gllate' Ihan given for the service limit the recommended course is to dete,mine the degree of weal on each camshaft journal bV measuring acron lIS diamete. with I micrometer 0' vernier

gluge and compare the ligur. obtamed WIth that given in the Specifications. If journal wear IS found to be mInimal. the internal dilmller 01 the cvlinder head beaflng surfaces mav be assumed 10 have worn beyond lim.ts. thus resulting in the need 10 replltce the cylinder head wilh a $Irviceable item. Before committing oneself to purchasing this relatiVillv ellpensiVfl component. double check the bearit'lg clea.ances and the de"ree of wear on the camshaft journals before confirmit'lg one'S worst suspicions bv measuring the inte.nal diameter 01 the cVlinder head bearing surfaces with the bearit'lg caps fitted and their 5e--19 'r- 18

, 1 3

Fig. 4 .2 S, . .ring hHd assembly - 400 mod.l. UPMf (o,1t I'Qk~ S rullng columnllowtJf '(akl!:

Low,,, b••"n9 ,ace

4

W/JShtJf

5 6

Righl -h/md helJdl,mp b,,,cket

7

8 9

Ltlll-hand fH!lIdlllmp /Jrllclt:tJ' CIJP - 4 olf Grommet 40" WlJshtt,

'0 Boll

"

"

Bolt

19 511''''9 WlShe, - 2 off 10 HlmdleblJI (/lImp - 2 off

N",

13 Spring wuhfJ:' 14 Upper yokl!: pinch bolt

,. 15

- 2 off WIJShfJ:f -

2 off

Spring w lishtJr _ 2 off

Il NUl - 2 off 18 Lo w tJr yoke pinch boll - 2 off

"

80ft - 4 off 11 Spong WUhf!:f - 4 off 13 8tJtlfmg IId/usttu ri ng

,.

UPPtJf "'1If1"9 'lief!:

25 Dust co~tJr 26 Lowe' yoke COVIN 27 HlIl!dltJOllr clllmp covr, 28 Plug _ 4 off

'30

Chapter 4 Frame end fork s

pIOYrde no .nfo rmatlOn as to the amount of set allo ..... ed Ofl the damper rod sprir>g before renewal '5 necessary If tn doubt as 10 the condition 01 the sprong ask th e advice of an oHicial SUluk, service agenT or compare I he Spl lng with iI new Item. 9 Closelv examine Ihe dust e.cluder for sphts 0' SIgns of de lerio/ alion. If de lec', ve. ,I must be renewed, as a ny Ingress of .oad grit wi n rapIdly aceeler8le Wflaf of the oil se al and fo,k 51!1nchlon It is advIs8ble 10 re new any gasket washers f illed

beneath screw heads as a millel of course, The same apphes 10 the O -tl ngs fitted beneath Ihe l Op c ap boll heild,. 10 Reilssemblv 01 the fOlk legs 15 essentially iI reve rsal of Ihe dIsmantling procedure whilst I'II)II"g Ihe following POints. II is essenlial Iha! all fork components I.e thoroughly wlI$hed In solvent and WIped c;lean wllh a lint -' ree c;loth before ISsembly lakes plac;e Anv I ral;ll 0 1 dIrt inSIde Ihe IOfk II!19 assemblv WIll QUlc;klV destroy the 011 se,1 or score Ihe st anc;hion 10 OUler fOl'k leg beam>g 5urfac;es 1 1 Belore filtlng Ihe new 011 seal. It should be ooated WIth the rec;ommended fork oil on its inner and o uler surfac;e,. This serves to make the fittIng o f Ihe seal In to Ihe lower fOlk leg easier and also reduc;es the l i,k 01 damage 10 the sea l whe n the fOlk . tanc; h ion is passed through i!. Great c;"e should be taken when f ilting the stanc;hion through the .eal. 12 Suwki lec;ommend the use 0 1 a servic;e tool I No 099 40-50 111 1 with wh ic;h to drive Ihe seal inl o the fork leg rec;ess. Wilh t he wac;er flng fitted the seal located pa rtiallv '" lIS rec;ess and Ihe fOl k . ta nc;hiof"l pas$lld through it the 1001. whic;h takes Ihe l orm 0 1 a short lerog th of me ta l tube aPOlO. imatelv 3 in long. WIth an inner dIameter JUSt gre81er th an the oute, diametel o f the stanch,on and an outer diameler just Ie.. than that 0 1 the ou l e' diamete ' o f the oil seal. may be passed ove, the s18nc;hlon and used to tap the seal home by using II as a lorm o f sl ide hammel If Ihls 1001 is f"lOt readilv available it can , of c;ou rse. be fablic; ated Irom a piec;e of metal tub ing of the appropria te dimensiOf"ls CI,e should be taken howeve!. 10 ensure that the end 0 1 the l ube that makes c;on tal;1 w ith the sell IS prOperlV c;ham fe red free 01 burrs and absolutelv square to the fork staf"lc;hion A lternatlvelv a sui table soc;ket ma~ be used to dflve the sea l '"to POSlhon before the S!ar"IC:hion is fItted . EnlJUre that the seal is driven home squarelv and IS properlv 'etllned in PO,itlon bv the Spflng c;hp 13 Refil the dampe, rod assemblV ,"10 Ihe sIar"IC:hlOn and relil the damper rod seat FIt the for k SPflrog(S) jand Spal;llr wherl filled ). lakirog call 10 Insert thlm wllh the c;oils in the same position as no ted dUflrog the dl,maf"llhng sequenc;e. On modlls WIth 8 single spllng fitted to elc h l ork leg. the smaUer diameter end o f the spring shou ld Iac;e the bottom of the lor k leg. Rlll t Ihe cap boll wllh ils O _lIng and tighten il fi nger-light This wilt serve 10 keep Ihe damper rod in pOsition during relitting o f the soc ket 5(;IIW InlO the wheel spIndle housing rel;llSS Insert the ."nc;hion into the fork lower leg and prep!lfe the soc;ke t screw lor insertion into the wheel spindle houSlrog 'e,," by degrellS irog ilS thre,d and filtlrog a new gasket wnher Rele. 10 the figure accompanying th IS lut and c;oa t the thread of Ihe sc;,ew WIth a thread locking c;ompOund and a 5ea!irog compound as shown before f illing It Into its ,ec;ess and lIghtenIng il 10 the spec;ified 10rQue loadIng 14 Re locate Ihe dUSI u c;lude, over the fork lower leg Refil the drain plug and gasket washer and unsoew the cap bolt Replenish the fork leg wllh t he correl;1 quanl itV o f l ork oil. Aele r to the Spec;ifications at the beginning 01 Ihis Chaplll. for bolh Ihe oil type and QUanlltv fo r lI&c; h model Ivpe. Fil the cap bolt and O-ring 10 the lork stanChion and nip it l ight The bol t s should be fullv t ighlllned to the spec;ified to'Que loading once th e fOl k legs have been refilled 10 Ihe mac;hine 15 The fork legs are now ready to be fitted 10 the mach,", but bel ore deong so. II IS worth ~U"rog II th is POinl 10 conside r Ihe advan tages o f fi llIng fOfk g'lters It IS a facI Ihal Ihe Iile of the oil le,' c;an be lenglhened conSlderabiv bv doing Ihll. w"h the aOdillof"l,1 adv,ntage thll Ihe lowel p,rt of Ihe IOfk s\tl nc;h,on is also oe cleaned of all grease by w'P'ng Ihem with a fuel soaked rag lak,ng the necessary fire precautions whilst doing so. If the bearings are see n to be breaking up 0' if they are cOfloded thlough ongress of waler due \0 lack o f lubrocal lon, Ihey may be d rifted oul o f pOsition. uSing a SUi table length of steel rod . 00 no t remove the bearings merely for inSpeCI IOn as The cages Will be damaged bV the drift. l ubrica te the ou lside 01 The new be aflng cages be fore driving them into place and ensure that they are filted With Ihe punCh marked lace oUl wa rds A sockel or short length of thick · walled me ta l tube with an e~ternal d'ameter which ,5 slightly less than Ihat of the bearmg Should be u ti lised to dllve the

134

Chapter 4 Frame and forks

bearing into place. This tool will serve 10 help keep the bearing SQuare 10 Ihe end 01 the swinging arm crossmemoor as it is fitted . 9 Check the pivot shaft for straightness bv rolling it on II flat surface such as a sheet of plllle glass. Alternative lv. place the shah on two V -blocks and measure the amoum of runout on Ihe sheft with 8 d ial gauge. lithe amount of runout found exceeds 0.3 mm (0. 012 inl. replace the shaft with a straight i18m. 10 Inspect the condition 01 the 1WO dust caps and thrust washe.s. if the caps show the slighlesl sign of damage o. deterioration then they must be renewed as they not onlv serve

10 keep grease in the bearings but wilter and road dirt oul. Worn bushes should also now bs .eplaced wilh new ilems.

11 Reassemble and .efO( ~he sWlOg lOg arm bV re\lers,ng Ihe remo\lal and dismantling procedures. A pply a molybdenum disulph ide g.ease 10 the cen ~ r a l space' the bearongs the bushes and Ihe inner edges o f the d",st caps as ~he ",no l is assembled Grease the leng th of the pi\lot shalt shank before Inse.tlng ,t ancamination. ,emolill Ind

1 Rea. suspenSIon unots o f t he hydraulically damped type are l,ueellO Ihe SU i ulr., GS and GSX models cOllered in th,s M anual Each unll Comprises a hvdraulrc damper effec l 'lie promaroly on rebound and a concen ,roc sprong It is secured to the f rame and sWinging arm bv means 01 rubber-bushed lugs 81 each end of tile un,1 The un,ts are prollided With an adjustment of the sprIng lension g.v,ng five senrngs The settings can be easliv allered w, t hou t . emov,ng the unotS from the machine by uSIng a tommv bal ,n the hole drrectly below t he sprongs Turnong cloc kwise will increase the sprong tenSIon and Sl iff en Ihe rear suspension. lurning anll clock Wise Will lessen the sprong tens,on and t here lore soften the rode As a general gUide Ihe softest setting is recommended when no pillion passenger is camed The hardest sewng should be used when a heavy load is camed . and during IHgh -slleed riding The inl ermedllte POs,t,ons m ay be used as conditIons dic t ate. 2 Th ere is no means o f draln,ng the un,IS o r l opping up. because l he dampers are buil l as a sealed unit If Ihe damping fa ils a. li lho Unil S start 10 leak. the complete damper assembly

11 Centre stand . ellamlnalion and sarvici ng 1 The cen tre Stand IS ,el aoned to I he underSide 01 the frame by two bol ts wh,ch serve 8S p,vo t shaft s. Each of I hese bol t s has a sprong washer located beneath liS head and is preven tOO hom leav'ng 115 re taIning nu t by a sprong clip wh,ch passes Ihrough the end of ,' s threaded sec t ,on A bush ,s filled between each plllOI shaft and ,tS con"e sl and re t a,ning lube 2 The PIVOt assembly on c entre stands is olten neglected w,th regard to lubrical,on and Ih,s w,1I even t uallv lead to wear It is prUde'l l to remove the p,wo t bushes from t,me to t,me and grease them tho,oughly ThIS w,1I prolong the effecl've life of the stand Check bef ore 'e l ,lI,ng the PlliOt shahs that the Spring washers are '101 flallened and are on good condition. they must be ,enewed ,I thev no longe, serve therr locking lunC loon Do not om,t to refit the sprong clops J Chec k thaI the re turn spllng is in good cond'tlon A broken or wea k spllng may cause Ihe stand to l all Whilst the machIne is ,n mOI,on with the resul t ,ng danger that once ,t ca tChes in some obstacle Ihe balance of the machone w ill be dras t ically affec ted

,~----------------------------------------~

Fig . 4 .7 Swinging .rm - all m odel.

,

S wmging .rm feulf

2

Bnlke torque .rm

3

Splicer

4

Needle roller be"ring - 2 off

5

Bush- 20ff

6 7 8

Thrust wuhv - 2 o ff DuS I up - 2 off

9 10 " ,2 13 14 /5 /6 17 18 19

22

WIIsn'r N", Pivot bolt Boll - 2off Spring wuhllr - 2 off "'ul - 20ff R.p,il - 2ofl R ighf·h 'IrId suspf!nsian un;l Lefr-hlmd suspension unit PlISSflngtJr 9rllb ' IIi/ NUl 4 off W.sher - 2 off

10 W"sne, - 5 off 21 W asher

4 off 22 W"sher - 4 off

•

"--

11

'\

"- -/

""

3

'\

6 7

9

10

5

17

.f ~ .. ~.

Chapter 4 Frame and forks

139

12 Prop stand : examination and s.rvicing 1 The prop st(lnd bolts to (I lug (I\t(lched to the rear 01 the left · hand lower frame lube A n e_lension sprong ensures tha t I he stand is re lracled when Ihe weight of the machine is taken off the st(lnd. When properly retraCled . t he st(lnd should be light against i ts SlOp and well ou t o f Ihe way 2 Check th(l t the pivot bol t is seCUIe (lnd th(lt Ihe pivot surfaces are well lubrica ted wilh either grease or mo tor oil. The e_tension spring must be free from fstigue snd in good con dition A serious sccident is almost inevilable if the stand ex tends whils t Ihe machine is on th e move.

10. 1 Ro tate the (ldjuster to aller Ihe spring selting

13

10 .4 Note the posi t ion 01 the pivot washers and grab rail end

Footr.sts : examination and r.novation

1 The front foo tre sts fi lted to the 250 modelS a.e o f Ihe borl~ on metal bracket type wilh renewab le rubber pads. If they are ben l in a spiu or I hrough Ihl machine fa lling ave •. they can be removed and straightened in a vice whilst he(lted to a dull red with a blow lamp. or welding torch. 2 The lronl loo lre sl s lined 10 Ihe 4 00 models and the p iUion footrests fitted to all models are pivoted on cl evis pins. Ihe fronl footrests only being spring loaded in t he down posit ion. If an accid ent occurs. It is probable th,u the lootrest peg w ill move against Ihe sp ring loading and remain und amaged. A bent peg may be detached from the mounting. efter removing the clevis pin secu ri ng spli l pin and Ihe tlevis p in itself The damaged peg can be str aighlened in a vice . uling a blowlamp fla me to apply heat at Ihe area wher e the bend occu rs. The l oo trest rubbe, will . of cou rse . h(lve to be removed as Ihe heal will render it unfi t 10' service. J NOle that If there '5 evidence 01 fa ilure 01 the metal ei ther bel ore 0' after straigh teni ng 11 is advised tha t the d(lmsged component is re newed. II a footrests breaks in service. los5 of machine control ;5 almost inevil able. 4 When refitt ing the cleVIS pin 10 a pwot,ng type 01 footrest assembly. ensure Ihst . where f,tted. the retum spring ,s correCI 1'1' located (lnd thai a new split- pin ;s used to reta in the cl evis pin ,n posi l ion .

14 R.ar b,aka pad.l.nd sh.ft .... mbfy : .xamination and ,.nov.tion

11 . 1 InSpeCI the cen tre stand spring and pivot points

1 Th. rea ' b rake ped.1 is secured bv a single pin ch bolt to the splined brake pivot sha fl . In Ihe evant 01 dam.ge. Ihe pedal mav be removed snd treated simi larly 10 a bent footrest I I describeJacket securing bolts. Remove the support brackel to fork leg secu ring bolts and lift the complete unit away from the machine Wilh Ihe unit placed on a clean work surlace. d.tach the caliper from it s support bracket by removing the twO already loosened securing bolts. 3 The caliper piston boot should now be prised out of position by using Ih. Ilat 01 II small screwdriver whiisl l ak ing care not to SCrB ICh the surface 01 the caliper bore. The piSlon can be displaced by applying an air Jel to Ihe hydraulic fluid leed orilice ollhe caliper. Toke g re Bt care not 10 use 100 high an air pressure when doing th is lind place a thick wad 01 clean rag over the end 01 the calipe r bore; this will serve 10 both catch the piston and prevent any Injury through hydraulic fluid being ejected fr om the caliper under pressure It is st ill. however, advisable 10 wear some form 01 eye protection during this operation. 4 Clean the caliper components thoroughly , only in hydraulic brake tluid. N .....r use petrol or cleaning soIvenl l or cleaning hydraulic brake parts otherwise the rubber components will be damaged Discard all the rubber compon.nlS as a mailer 01 cours • . Th. r.plac.ment COst is relatively small and does not warrant re-use of components vital to safe ty . Check Ihe piston and caliper cylinder bo'e lor fCOfing , rUlling or pitting. If Iny of these delecls lie evident it i, unlikely thll a good fluid sell can be maintained and for Ihi, reason the c;omponenlS should be .enewed 5 Renew the two spindles With lheir rubber boolS from the !>Jake caliper support !>Jackel by pulling them from position. Clean the spindles and th.i, retaining bore, wilhin the support b.acket and Ulmine th. rubber boots 10' Iny signs 01 damage or deterioration" necessary. ren.w any Items that appear to be in a ooubtful condition, before applying Su~uki broke grease to the length o f each splndl. and refilling Ihem to the bracket. NOle 11'1111 the spindles differ Insomuch IS the lower o f the Iwo has a slightly stepped shank

6 Assemble the c;ahper 1,1",1 by reverSing Ihe d.smanlling sequence When assembling pay partlculal allention 10 Ihe followlng pornts. Ensure thaI dUling assembly all the companents ale kepI absolutely clean Apply a generous amount of brake fluid 10 Ihe inner surlace of Ihe cyllndef and to Ihe peftphery of the poston then assemble 00 not assemble lhe oiston Wilh It inchned O. tWISled When inSlalllng the piston push il slowly .nto the cyllnde. while tak.ng care not 10 damage the piSlon seal 7 With bolh Ihe caliper and SlIPper1 blacket serviced and reassembled , ;orn the two components logelher by .efitting the two retaimng bolts linger -light ReIer to the figure accompanying thiS te.t and note the po$.hon of the shim. guide and SOftng plates. Refit the complete as.sembly to Ihe lork leg and trghlen bolh the fo.k 10 support braCket and Ihe bracket 10 caliper unit securing boilS to the speCified torque load.ng 8 8efore reconnect.ng Ihe brake h05l! union 10 the caliper check the condition o f the two gasket washers located one eilher side 01 Ihe union, Renew these washers if necessary and fit and lighten the union bol t to the recommended l orque loading 9 81eed the brake aller re lililng thll .eservoir with new hydraulic brake "uid, then check for leakage while applying the brake lever Push the machine forward end bring it to a halt by applying the brake 00 this several times to ensure Ihal Ihe brake is opera t ing correc t ly belore taking the machine for a test run. During the run , use the brakes as ohen as possible and on complelion rechec;k for signs of fluid loss

7

Fr o nt diac brake m ailer cylind81 lion. renovetion Ind refi n ing

removal . ellamina·

The masl er cylrnder and hydraulic reservOlllake Ihe form of a combined unit mounted on the right · hand s.de of the handlebars 10 whic;h lhe Iront brake lever and SIOO lamo switch are allached The master cylinder .s ICtuated by Ihe f,ont brake leve. and a~hes hydraulic pressure Ihrough Ihe system 10 operate the f,ont brake when the handlebar lever .s mampu lated The master C\lhnder pressurises the hydraulic "uid in the buke pipe whiCh. being IncompresSible cau5l!s the PIston to move .n the c;altper unll and apply the IftCloon pads 10 the brake If the mailer cyhnde, seals leak hydrauliC plessure will be lost and Ihe braking aCllon rendered mUCh less effett.ve 2 8eto.e t he maste. cyhnder can be removed Ihe system must be drarned Place a clean con18lner below the caliper unil 1

150

Chapter 5 Wheels. brakes and tyres

16

14

10

13

Fig . 5 .3 Front brake ce liper - All m o del s

1

2

2

6

3 4

5 6 7 B

9

1

7

10 II

12 13 14

9

15

16 17 IB

19

Brake pads Support b'llcket Piston boot Pis/on seal Piston Upper spindle Lo wer spindle Cllliper Shim plate Spring plll/e Boll - 20ff Pad guide Rubber bOOI - 2 off Boll Washer - 2 off Union boll Pad inspection window Bleed nipple Bleed nipple cap

5

11 and ilHIlCh II plastic tube from the bleed sc rew on lap of the

caliper unit to the cont ainer. Open the bleed screw one comple te turn and drain Ihe system bv oPIra l ing the brake lellor unt,l the m1lS18' CVlinder reservoi r is emplY. Close the bleed screw ilnd remove the pipe 3 Place iI pad of clean tag beneath I he polnl where the brake hose adjoins the master c"linde. , This Simple precaution is eSSenlial !O prevent brake f luid dnpping onto. lind therefore damaging. plastic and painutd components IOC81& To remove the sprocket, bend beck the locking tab at each end of the washers and undo the nuts. 2 The sprocket need only be renewed if the teeth are hooked, chipped, broken or badly worn. It is considered bad practice to

fenew one sprocket on its own; both drive sprockets should be renewed as III pair. preferably with a new final drive chain. If this recommendation is not Observed. rapid wear resutting from the running 01 old snd new pans logether will necessitate even earlier replacement on thl nlxt occasion. 3 Fitting of the sprocket to the cush drive hub is simplv a reversal 01 the removal procedure. Do not rebend the locking tab previously used; il necessary. renew the tab washers . Tighten the sprocket retaining nuts to the torque figure given in the Specifications Section 01 this Chapter belore locking them in position. 17 Final drive chain cat ion

15. 1 Eilich cush drive rubber may be removed for renewal

Ix'min'tion. adjustment and lubri-

I A s the final drive chain is fu lly exposed on all models it requ ires lubrication and adjustment at regular inteNals. To adjust the chain place the machine on its cen tre stand and take out the spHt- pin from thl rlar wheel spindle and slacken the spindle nut. Slacken also the nuts securing the brake torque arm. Undo the locknut on the ch ain adjustlrs aod turn the adjuster bolts inwardS to tightln the chain. Marks on the adjusters must be in line w ith identical marks on the framl fork to align the rear wheel correctly. A final chick can be made by laying a straight wooden ptank alongside the wheels . each side in turn. Chain tension is correct if there is 20 - 30 mm to.8 1.2 int of slack in the cln tre of the lower chain run. 2 Note that a cha in that is run exceptionally slaCk may strike the gear indicator switch which is retained on the gearbox wall . If thl switch body breaks. l ubriCl;1n1 loSS from the gearbox may endanger the continued good health o f the gearbox components. Do not run Ihe chain over1ight t o compensa te for uneven wear . A tight chain will place excessive stresses on the gearbox aod reSt wheel bearings leading 10 their early failure. It will also absorb a surprising amount of power. 3 Alter a period of running . the chain will require lubrication. Lack of oil will accelerate the rate of wear of bo th chain and sprockets and will lead to harsh transm ission. Thl application of engine oil will act as a temporary exped ient. but il is preferable to use one of Ihe proprietary graphited greases contained within an aerosol can. Th is tVpe of lubricant is thrown off the chain less ea$llv than engine oil. Ideally the chain should be removed at regula, inteNals. aod immersed in a molten lubrication such as linklyfe 01 Chainguard aher it has been cleaned in a paraffin bath. These laller lubrican t s achieve better penetration of the chain links and rollers aod are less likely to be thrown o ff when the chain is in motion Because the chain fined as original equipmenl is of the endless type. th at is il does nOI conlain a spring master link. il should be appreciated thai chain removal is a fairly complicated procedure which necessi tates detaChment o f the swinging arm asssembly if the chain is to be removed withotJt it being pafted by use of a chain splitt ing tool. Because of this. it is obviously not desi rable 10 keep removing the chain lor l ubrication. or to remove the chain so that it may be chec;ked for wear. To carry out a check on the amount 01 chain wear with the chain tilled to Ihe ma chine. wash the chain down with a petrol- soaked rag and stretch the c;hain to it s full length by turning the adjuster bolts in wardS. Select a length of chain in the middle of Ihe chain run and count out 21 pins. that is. a 20 pitch leng th . Measure the distan ce between the lst lind the 21st pin II l hls distance exceeds the SltVlI;e IlInll o f 32 4 3 mm ( 12 77 In), the cham must be renewed Note ,hat thiS ch-eck

Tyre changing sequence -

tubed tyres

Deflate tyre. After pushing tyre beads away from rim flanges push tyre bead into well of rim at point opposite valve. Insert tyre lever adjacent to valve and work bead over edge of rim.

Use two levers to work bead over edge of rim. Note use of rim protectors.

Remove inner tube from tyre.

~ When first bead is clear, remove tyre as 0 shown.

When fitting, partially inflate inner tube and insert in tyre.

Work fi rst bead over rim and feed valve through hole in rim. Partially screw on retaining nut to hold valve in place.

Check that inner tube is poSitioned correctly and work second bead over rim using tyre levers. St art at a point opposit e valve.

Work final area of bead over rim whilst pushing valve inwards to ensure that inner tube is not trapped.

~

162

Chapter 5 Wheels. brakes and tyres

should ALWAYS be made aile. tile chilln has been washed 001. but before any lubricant 15 apohed otherwIse the lubrocant may l ake up some 01 tl'M! play 4 1\ 1\ is found tha i the chain f,ued as 0"9lnal equIpment IS stre tched beyond 'im ilS The chain must be renewed, if neeess

I fy . with replacemen t sprocke ts. The original cham is of the en(lIess type without III joinmg spring link end 10 allow removal of the chain and fin ing of 11'10 new item the sWlngong arm must be detached. Refer 10 Chapter 4 fo r delails. Some thought migi'll be given \0 fin ing e chli", with a Spring link Allhough th,s ,n,roduces a weak poin t in the chain i\ does allow eas.,. cham removallOf periodic cleaning and efficien t lubricatIon whIch WIll Increase the chain's service life Subsequent chain reflewal .$ made easier too. II this coorse of aClion is chosen Ihe old. endless Iype. Chain can be removed by displacing a link pin

using a chain-breaking tool This will overcome the need IOf swinging a rm removll 5 When filh ng a cha in wh.ch IOcorporates a spr.ng link. mike Surll Ihal Ihe spring link 'S 5ealttd COHlII;:IIV. with the closed lind la cing Ihe di rection 01 Ira vel. 6 NOle Ihal replacemenl c ha ins are now available in standard metriC sizes from AenoId Limited. the BriliSh chain manufa cturer When ordering a new Chain. alwavs Quole the si~e . the number of chai n links and Ih e IVpe 01 machine 10 whi ch Ihe chain is \0 be filted 7 Reme mbe •. on completion 01 uamination and II necessary adjustmen t o r replacemenl of Ihe chain. 10 ensure Ihal bo th adjuster bolts are locked in position by tighl ening Ihe" locknuls The wheel spindle re ta ining nut shoold be lightened 10 Ihe tOfQue loading specified at the beginning of Ihls Chapter and locked in position by IIlI ing a new spli l-pin. Ftnaliv. SPIO Ihe rear wheel 10 ensu re Ihal il rotetes IreeiV . IdlUSI Ihe rear brake ope rat ing mechanism if necesHry and retighten the 10'Que IIrm retaining nuts.

18 TVre, : tem ovlI l and fiu ing

AI some time or olher Ihe nettd will a.ise 10 remove Ind Iflplace the Iy.e •. either I I a resul t of II punClure o . because re placemenlS are necenary 10 o ff set wear To Ihe lOexpeli enced. tyre changing reprfls.entl I form id a b le lask. vet if a fflw Simple rules are observed and Ihe technique le a rned . the whole operation il surprisingly simple. 2 To remove Ihe lYl e f.om eilher wheel. lirSI detach Ihe wheel from Ihe machine. Deflate Ihe Iy. e by lemoving lhe valve lOser! Ind when il is fullv defllted. push Ihe beed from the tyre awav from the whl!'l!l rim on both Sides so that Ihe bead enters Ihe cenlre well o f the rim Remove Ihe locking cap and push Ihe tyre valve inlO the Ivre 'Isell 3 Insen a lyre lever close to the vllve and lever Ihe edge 01 Ihe lyre over th.e oo lside 01 Ihe wheel rim Very little for ce ,hoold be necessary: if resiSlinCe II encounlered II IS probably due to the facI Ihe lyr e beads have no t entered Ihe well of Ihe wheel rim 1111 Ihe wly rOund Ihe 1'1'111 NOle that while ,he mlchine is ti ll ed w it h CIISI 1110'1' wheel s. Ihe risk of dllmllge 10 the wheel rims can be m inimls.ed by Ihe use of proprietary pllslic rim protectOfS pllced 0'1'111 the rim lIange 81 Ihe point where Ihe tyre ItWers lie inserted. Suitable rim prOteC tors mlY be fabr lClted \lery easily fr om ShOfI lenglhs 14 - 6 Inchesl o f Ihick -willed nylon petrol pipe which hive been $PIli down one Side uSlOg a sharp knife . The use 01 rim prOleCIOrs should be adopted whenever ItWelS are used Ind. Iherelolll. when the risk o f damage is li kely. 4 Once the tyre has been edged over Ihe wheel flm . II IS elsv to w ork Iroond lhe wheel rim so thllllhe lyre IS completely free 10 one side. At th is stlge. Ihe inner lube can be removed 1

5 Working tr o m lhe olher s,de of the wheel. e .. se Ihe olhel edge 01 Ihe lyre over tlioe OutSIde of the wheel n m that ' 5 lullhesl awav ContlOue 10 work around Ihe rim unlil Ihe lyre is free compieleiv from Ihe flm 6 "a punClure has necesSltaled Ihe lemoval of Ihe tvre rll ,nflale Ihe Inner tube and immerse il In a bowl o f water to trace Ihe source of Ihe leak Mark ils posilion a nd deflate Ihe lube Dry Ihe tube and clean Ihe I rea I roo nd the puncture Wllh a petrol soaked .ag When the surface has d ried. "POly .ubber solu\lon and allow Ihis 10 dry before removing Ihe backing from Ihe Pilc h and applYing Ihe patch 10 Ihe su rface 7 II IS best 10 use a patch o f self-vulcanising type. which Will lo.m a very permanent repalf . No te ,hat '1 mav be OIICeSSilry to remove a protective COVllflng from Ihe too surface o f the patc h aftel It has sealed into position. Inne. lubeS mlde from Iynlhellc rubber may reQuire II $pIIcial Iype of patch and Idhesive. if a satisfactory bond is 10 be achieved 8 Before refilling Ihe tvre check Ihe inside 10 make sure that Ihe object which Uused the punc lure IS not trapped. Cheek Ihe o u lside of the lyre parl icullrly the Ir ead area 10 mak" sure nO lh tng ' 5 trapped Ihat mly Cluse a further punClure 9 II Ihe Inner tube has been palched on a number of pasl o ccasions or II Ihere IS a tear or large hole. il is prefe.able 10 dlSClrd il and fil a new one Sudden defla lion mly clluse an a ccKlent particularlv if il occurs w ith Ihe front wheel. 10 To III Ihe lyre. infllle Ihe inner lube sufficienllv for il 10 aSSume a clfcular shape bul only juSI Th.en push il inlo Ihe lyre 50 Ihal II IS enclosed completely lilY the lyre on the wheel 81 an IngJe and .nsen lhe vall/ll throogh Ihe .im lape .nd Ihe hole 10 Ihe wheel rim. All ach lhe lock ing cap on Ihe first few Ihrelds s ufficien l to hold the vilive cllp tlve 10 its COf.eel location. , 1 Stirling at the point lun lioeSt from the valve. push Ihe tyre belld over Ihe edge 01 Ihe wheel rim un lil il is located in Ihe cenlral well Conlinue to work around the lyre in Ihis flshion until Ihe whole of one side o f th e lyre is o n Ihe rim . It mlV be necessarv 10 use a lyre levlII during the final s l.. ges. t 2 Make sure Ihal Ihere is no pull on Ihe lyre valve and aga in commen cm9 With the .rea lu'theSt f,om Ihe valve. eese the Olher bead o f Ihe 1'1'111 over the edge ollhe rim. Finish Wllh Ihe arel close 10 Ihe valve. pushing Ihe vll\le up into the lyre unl ll Ihe IOClung cap louches the rim . This will enSl.lre lhe Inner tube IS nOI Irapped when Ihe 1111 SecllOn of Ihe bead is edged over Ihe flm Wilh a tyre ItWe. 13 Chec k Iha l Ihe inner lUbe is 001 trapped at any poonl Re.nfllte the inner tube. Ind check Ihll lhe tyre is seiling cOfreclly aroond Ihe wheel rim There should be a Ihin rib mou lded aroond Ihe Will of the tyre on bolh sides. which Should be eQuidiS!an l Irom the wheel 11m 8 1 III poinlS. II the Ivre IS unevenlv localed on Ihe rim . Iry bounCing Ihe wheel when Ihe lyre is a t Ihe recommended pressure It.s probable th81 one of Ihe beads has no l pulled clellr of Ihe cen lre well. 14 Alwlvs run lhe ly res 11 Ihe recommended pressures Ind never under O. ove,-inllite The COffect pressures Ire give n In Ihe SpeclficallQflS SeCl'on 01 Ihls Chapter 15 Ty.e repla cemenl " I ided by dusttng Ihe side Wills plrl lC U' larly 10 Ihe vic.nlty of Ihe belds w ith " libera l coattng of lrench chllk Wash.ng-up liquid Cln liso be used 10 good effe cl bu, Ih,s has lhe disadvantage 01 ClluSlng the inner surfa ces of Ihe wheel tim 10 corrode 00 1101 be over gene,oos in Ihe aoollO;:I· tion of lubncant o. Iv.e creep mlV occur 16 On machtnes eq uipped wilh wi. e -SpOked wheels. never I" Ihe lOner tube and lyre w ilhout the , im lape In positon. If Ihls precaulion is over looked Ihllle Is good chlnce of Ihe ends ollhe spoke n,pptes chaling Ihe inner lUbe Ind clusing s crop o f punc tures. 1 7 Never lit a lyre thll hilS. damlged Ifead o r side Wills Aplrl 'rom Ihe legit ISpeCts. there il I very grel1 ris k o f a biowou l which Clln hive 51"OOS consequences on any two wheel vehicle 18 Tvre valves 'llrely glVetroobie. bul il is alwlYs advisable 10 che ck whelher Ihe valve its.ell i. lelking belore removing Ihe Iv.e Do oot fOfgll! to fit the dUI' cap which forms In effeCl Ive second $11 .. 1

Chapter 5 Wheels. brakes and lyres

,

;~;:;:

ume mark S on each l o.k e!'ld

163

each adjuster bolt ,n PO$ll'on' . -

locknut

20 Whee' balancing

----- ---- ---

c

-- ---- - - ------- - -

-- -

- - -- -

--

Fig. 5 .8 . Method of c hecking wheel alignment

A & C . Incorrecf

19 Tyre vllve du"

B - Co,,&(;1

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j.

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