Time to get all six of those mighty pistons back in their respective homes, eh Ralph? Project Kawasaki Z1300 part 6
Ralph gets further on with the mighty six.
Time to get six big pistons in their rightful home: and let’s face it, fours can be awkward enough! More of that later: first up I removed the oil restrictor jet from just behind No. 4 crankcase mouth to ensure that it was clear and without debris. It’s a curious little chap, but I washed it with brake cleaner and blew it through with my airline (while wearing safety glasses/mask of course). My tip if you’re new to tools: Google the safe use of such items before you become a further burden to the NHS. Next job was to clean up the pistons which had the usual cloak of carbon over the crown. The easiest way to remove this crud is with a rotary multi tool such as a Dremel with a little wire wheel. The only down side I have found with this method is that the wheels seem to moult and you find yourself being stabbed by the disembodied wires that have become embedded in your clothing. Once the crowns were freed from their carbon prison, I gave all six pistons a swim in the ultrasonic cleaning tank, which removed the remaining filth. I then broke out the genuine Kawasaki piston rings. Firstly, I fitted the oil control spreader ring that keeps the two oil control slider rings in position which I fitted next. Lastly I fitted the compression rings being mindful to ensure they were the right way up. Now it was time to fit the part that caused all the trouble in the first place, the water pump drive plastic bevel gear. After lubricating the bearing surfaces, I installed the gear into the block. These gears have been unavailable from Kawasaki Heavy Industries for many years, which is very annoying considering what a short life they seem to have. Any NOS (New Old Stock) gears were snapped up
many moons ago and there are no pattern ones available in the UK. I thoroughly investigated getting some made, but discovered that those with the ability to cut bevel gears are very thin on the ground and those that are kitted up, charge like a wounded rhino for the benefit of their skills. From my own researching, there is only one place in the world that can help out with this part and that is www.z1300.de. They are available as an exchange item where you send them what’s left of your bevel gear and they bond a new plastic bevel gear to the hardened steel part. As we are still in the EU I had to pay the full €189 and probably a bit of carriage. Cheap these parts are not, but the quality is first rate and the despatch is brisk, though they will not send out your new one until they have received the duff one. I fitted a new oil seal into the block for the water pump shaft and carefully fitted the shaft from the front and replaced the drive pin. I then installed the steel bevel gear, engaging it with both the plastic gear and the drive pin on the shaft. There are suitable flats on the shaft to attach an opened spanner to prevent the shaft turning while you reattach the securing nut and tighten it up. I torqued it up to the prescribed setting of 14.5lb-ft. I slid the drive shaft in from the left-hand side, engaging the male shaft spline in the corresponding female in the gear. I then fitted the securing bolt through the round window on the right hand side of the block. The remainder of the coolant pump drive system is fitted once the block is fitted back on the crankcases. All these bolts were given a dab of thread lock and seal to prevent them from abandoning their posts without leave and causing horrific engine damage. I was now at the stage I had really not been looking forward to – installing six pistons in their barrels; to this end I thought I would minimise the potential for misery by getting myself kitted out properly before starting. I can tell you from years of experience that there is only one safe way to fit rings and that is the right way, using proper ring clamps; they’re not even especially expensive! There was no way my normal home brewed tools for holding pistons at TDC (Top Dead Centre) were going to work on a six, so I breathed in hard and sourced the proper Kawasaki factory special tools which were difficult to trace and at a not inconsiderable cost, particularly with several lots of international carriage involved. Believe you me though, when I came to doing the job I was hugely relieved that I had been able to overcome my natural miserliness!
I fitted the special tools as specified in the manual with Nos 3 and 4 at TDC. I fitted ring clamps to 3 and 4 as they would be first to dive into their requisite tunnels of love. I buttered up the mating surface at the bottom of the block with Wellseal and also the bottom of the base gasket as I didn’t want to risk any leaks. I attached cords to both the cam-chain and the water pump drive chain. It’s a right old faff trying to keep the cam-chain in the correct position as it has a tendency to get itself in the wrong place. If you do one of these, you’ll know what I mean. I stuck the base gasket to the underside of the block out of the way and employed the services of SWMBO (She Who Must Be Obeyed) to help me get the block in position and drop it down on the waiting and eager pistons. The first two slid into their bores with relative ease and I removed their ring clamps and attached them to 2 and 5. I only have two sets of ring clamps in my workshop because until you work on a six, that’s as many as you need! Luckily I have a tool business so was able to rob another two sets from stock! I added clamps to 1 and 6 and we were ready to roll. We gently eased the block down over the four remaining pistons simultaneously keeping it level at all times, little by little tapping each end of the block with ultralight blows with our hands as the liners slid the ring clamps down as the rings entered the bores. Using the factory tools, the job was actually far easier than I expected and before long we were dismantling the clamps and pushing the cylinders down into the crankcase mouths.
I engaged the water pump drive sprocket with its chain and slipped the sprocket over the end of the shaft, securing it with a bolt. I made sure that the cam-chain was again in the correct alignment. I coated the top of the cylinder block and the bottom of the head with Wellseal, fitted the head gasket and then dropped the head on after checking all the dowels were in their correct places. I fitted new copper washers where required and stock steel washers where applicable, followed by the main cylinder head nuts and the remaining M6 bolts. All fasteners were torqued down in stages, in the prescribed sequence shown in the diagram in the factory workshop manual. I tend to do more small increases in torque than specified in the factory manual to ensure that such a long casting is never stressed; it might not be essential, but given the rarity and expense of major parts on classic bikes I’d rather be over cautious than sorry. Even when I reach the final torque I still keep torqueing them as the head gasket does tend to compress and a few laps with the torque wrench is essential until the final torque is achieved. Next month I’ll start playing with cams and tensioners.
Six go swimming.
Cleaning a piston crown while simultaneously creating automatic acupuncture clothing.
Oil restrictor jet removed for cleaning.
The plastic driving bevel gear in position and the water pump shaft with gear attached and nut started.
The villain of the peace – the sole reason for this whole rebuild!
Fitting the compression rings with piston ring expander pliers.
The first oil control ring.
…and look what you get!
Only £57.52 per piston…
All the pistons lined up facing north ready to dive into the block.
Tightening up the bolt with a torque wrench. Note: I did not actually rest the spanner on the machined face while tightening as this could cause damage, but I needed a free hand for the camera.
Pushing in the drive shaft through the replacement plastic bevel gear.
Gently doing up the nut with a cranked ring spanner before torqueing up.
Doing up the bolt securing the drive shaft to the gear.
A genuine set of Kawasaki special tools to fit the pistons in the bores.
Head gasket in place, cam chain idler sprocket in place and wrangling the cam-chain into the correct position before dropping the head on.
Painting the block mating surface with Wellseal.
Applying Wellseall to the bottom side of the base gasket.
The cylinder head back on its throne awaiting the torqueing down sequence.
All the pistons are now safely in their bores. At long last!
Attaching a ring clamp to piston number 2. Steady as she goes...
Pistons 3 and 4 are in and the ring clamps removed.
Applying Wellseal with a cheapo ‘artists’ paint brush.