Ralph sorts out the tim­ing.

Classic Motorcycle Mechanics - - CONTENTS - www.bik­er­stool­box.co.uk www.zed-parts.com

Af­ter re-hom­ing all six pis­tons last time out, this month I am go­ing to fit the cam-shafts and set them up to open and close the ex­haust and in­let valves at the op­ti­mum time and the pre­cise amount in re­la­tion to the six re­cip­ro­cat­ing pis­tons. It’s not as hard as it sounds. Be­cause the cam-shaft sprock­ets are ma­chined out of the same lump of steel as the shafts them­selves, so there is no temp­ta­tion to make life hard for one­self by slot­ting the sprock­ets to dial them in. Un­like ear­lier Zeds the Z1300 em­ploys a silent style cam-chain. Ear­lier mod­els used tra­di­tional roller chains sim­i­lar to the drive chain, but ob­vi­ously much more diminu­tive. The end­less silent chain used is more durable than a roller chain and is con­sid­er­ably qui­eter in op­er­a­tion. The sprock­ets are more like gears and seem to be less sus­cep­ti­ble to wear than the tra­di­tional roller chain sprock­ets – which is just as well given the fact that you can’t change them on th­ese cam-shafts. Be­fore fit­ting the cams, I set the crank­shaft to TDC (top dead cen­tre) on bores one and six. I find that the eas­i­est way to do this is to look down the spark plug hole on num­ber six to de­ter­mine the pis­ton po­si­tion. If you’re not re­mov­ing the cov­ers from the end of the crank­shaft, then the least painful way to turn the en­gine over is to put the bike in top gear with the bike strapped down to keep the rear wheel off the bench. Get­ting it into sec­ond is tricky on a Kawasaki as you have to have the fi­nal drive turn­ing to get it into sec­ond. It can be achieved with a bit of de­ter­mi­na­tion and ide­ally a sec­ond pair of hands spin­ning the back wheel while you hold the clutch in and get it up into sec­ond. I then care­fully rest a long thin screw­driver on the pis­ton crown, through the plug hole, so that I can see what part of the cy­cle the pis­ton is at. If you’re go­ing to do this, en­sure that the screw­driver can’t slip and get jammed i.e. keep it as close to ver­ti­cal as pos­si­ble. On this bike, the A5 model, there is a lit­tle in­spec­tion win­dow in the al­ter­na­tor cover, which can be opened by re­mov­ing a cou­ple of coun­ter­sunk JIS screws. Through this open­ing you can see a pointer and the tim­ing marks en­graved on the out­side of the al­ter­na­tor ro­tor. There are three marks ‘T’ for TDC, ‘F’ for fir­ing point and a last line in­di­cat­ing full ad­vance­ment of the ig­ni­tion, which is used when check­ing the ig­ni­tion tim­ing with a stro­bo­scope or tim­ing light. For the pur­poses of set­ting the valve tim­ing I used the T mark. I then fit­ted the ex­haust cam with the tim­ing mark on the sprocket in line with the top of the head, en­sur­ing that there was no slop in the chain from the drive sprocket. Next you count the num­ber of chain links and en­gage the 17th link with the ex­haust cam sprocket in line with its tim­ing mark, as shown in the di­a­gram. At all times in the process the chain run from the drive sprocket

must re­main taut or the tim­ing will not be cor­rect. Once you are sure that the cams are in the ap­pro­pri­ate po­si­tion, the cam caps are fit­ted and grad­u­ally tight­ened down evenly so as not to put un­due strain on the shafts. I can­not over em­pha­sise the im­por­tance of us­ing a good, ac­cu­rate torque wrench to fi­nally tighten them. The stan­dard cam-chain ten­sioner on the mighty six has al­ways been much ma­ligned and most will have them re­placed with a su­pe­rior item from the mighty ZRX1100/1200. The part num­ber is 12048-1113 with a cur­rent Kawasaki price tag of £83.99. One point is that the spring should be short­ened by 10mm as it will put more pres­sure on the cam-chain than is de­sir­able on the big six. This valu­able nugget came from Oz at Zed-parts who has an en­cy­clopaedic knowl­edge of Kawasaki’s gi­ant six. He sells lots of parts for the Z1300 on his web­site. While mine had the up­graded ten­sioner fit­ted, the spring was still the same length as stan­dard, so I clamped my small air

abra­sive cut-off saw in the vice to re­move a short length of spring. Had I not had the air grinder I could have used a ro­tary multi tool with an abra­sive cut-off disc. I then reat­tached the ten­sioner main body to the block with a gas­ket and Wellseal hav­ing re­leased the stop­per and pushed the plunger back into its body. The ten­sioner should be fit­ted with the ar­row point­ing up­wards. I was then able to re­fit the spring and pin. The cap was then re­fit­ted with an an­nealed cop­per washer and a torque of 14.5ft/lbs ap­plied. I needed to make a new gas­ket for the water pump chain ten­sioner, so I cut a big hole in a piece of suit­able gas­ket ma­te­rial with my cork borer kit and fit­ted the ten­sioner through the hole and rubbed and pen­cilled around the body to trans­fer the shape and bolt hole po­si­tions to the ma­te­rial. I used a smaller cork borer to cut the 6mm bolt holes and the in­ter­nal radii for the outer shape and fin­ished the shape with a scalpel with a 10A blade. I then but­tered up both the block and the part with Wellseal and bolted it back in place. Re­plac­ing the sump is not an easy job, if like me you have the bike on the cen­tre-stand. The cen­tre-stand is the best way to support the bike, un­less you want to fit the sump. I also had the same fun and games tak­ing it off ini­tially. Luck­ily for me I have a pro­fes­sional bike bench with a lift­ing arm or I would have had prob­lems. I sup­ported the front lower frame rails on both sides with large blocks of wood on top of a bike lift­ing jack. I at­tached the rear frame of the bike on both sides to the lift­ing arm and then dropped the bench down so that the deck dropped be­low the stand so that it could be flicked out of the way al­low­ing me to fit the oil pan back in place and get a cou­ple of bolts to hold it be­fore push­ing the stand back down to take the weight of the bike again. I sup­pose po­ten­tially those with­out the lift­ing gear may be able to put the bike on the side-stand and fit it while grov­el­ling around their garage floor, but I’m way too old for that level of dis­com­fort. I’m sorry not to have taken pho­tos, but when I have a heavy bike dan­gling at

height above me – photography is rarely at the fore­front of my mind! I am a big fan of stain­less bolts on my bikes, but us­ing stain­less fix­ings in alu­minium al­loy or even in stain­less steel nuts is not with­out its pit­falls. I don’t un­der­stand why it does it, but stain­less threads have an an­noy­ing habit of ‘pick­ing up’ or ‘galling.’ This is where a dry thread will sud­denly jam solid as the threads sort of par­tially weld them­selves to­gether, par­tic­u­larly when very dry. A pre­ven­ta­tive mea­sure is to lightly coat the screw thread with an anti-galling paste such as Nickle Slip. I used all stain­less cap screws to at­tach the sumps so I treated all the screws with Nickle Slip, be­fore tight­en­ing them up with my favourite ¼in drive elec­tronic torque wrench. The price of Nickle Slip seems to fluc­tu­ate wildly, so it really is worth shop­ping around – we cur­rently don’t sell it at Biker’s Tool­box I’m afraid. I gave the in­let stubs that con­nect the un­usual large twin-choke CV car­bu­ret­tors to the cylin­der head a very good clean. I even bead-blasted the face that mates with the head. You really can’t risk air leaks here. I in­spected them closely for any signs of per­ish­ing, which pro­pi­tiously there was none to be found – rather a re­lief con­sid­er­ing there are no new ones to be had, even for ready money. I gave the mat­ing face a good scrub with brake cleaner, fol­lowed by the same treat­ment for the op­po­site side of the joint on the cylin­der head. I ap­plied an even cov­er­ing of RTV sil­i­cone to the face of the stubs be­fore at­tach­ing them to the cylin­der head to pre­vent any air leaks. There was ac­tu­ally a spe­cial Kawasaki ser­vice jig avail­able back in the day to hold the stubs in per­fect align­ment for this job. The other side of the jig was also used to achieve per­fect lo­ca­tion of the car­bu­ret­tors when split­ting the sep­a­rate bod­ies and re­build­ing them as a bank again. I have never seen one for sale so I had to man­age with­out. Next month I’ll re­build the er­rant water pump.

A silent chain is durable and, as the name sug­gests , it is quiet.

Mea­sur­ing the cam-chain ten­sioner spring.

17th link Set­ting the cams cor­rectly. 1st link

Tight­en­ing down the cam caps evenly.

Torquing down the ex­tremely vul­ner­a­ble cam cap bolts.

The crank­shaft set at TDC on 1 & 6 cylin­ders.

Us­ing a smaller cork borer for the bolt holes and the radii for the shape cut­ting.

Cut­ting down the spring us­ing an air-pow­ered disc cut­ter.

Re­fit­ting the pin, spring and cap to the cam-chain ten­sioner.

Mak­ing the first big hole for the gas­ket us­ing a cork borer.

Ap­ply­ing RTV sil­i­cone to the twin-choke carb stubs.

The fin­ished gas­ket.

Bolt­ing up the water pump drive chain ten­sioner.

Tight­en­ing up the car­bu­ret­tor man­i­folds to the cylin­der head.

Cut­ting the outer shape with a scalpel.

Ap­ply­ing Nickel Slip to the threads of a stain­less cap screw.

Torquing up the cap screw at­tach­ing the mighty sump to the crank­case.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.