Ralph sorts out the timing.
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.