Z1OwnersClub GB

Is the starter clutch supposed to turn easily with the crank bolt tight, I have the middle size damper fitted, can't find the original one, so guessed at the size.
Cheers Rob

Rob, the starter clutch gear-wheel should turn with a slight about of drag, in one direction with the crank bolt tight. The damper (comes in 3 different sizes) and is merely to provide drag and to avoid rattle.

I think they could wear-in, if the damper is little tight. This would have to be a "gut" judgement , whether or not to go to the smaller size damper.

RegardZ

Cheers, I will probably rub the surface of the damper down, to see if I can get the right amount of clearance.

Regards Rob

Rob, to obtain the right drag, I have used a piece of glass and a sheet of emery to carefully remove the sharp edge of the rubber. It is a pain in the ass re-tightening each time to check if it's right. Good luck!
RegardZ.

I have found the original damper and it is a 1*, however even when this is fitted the clutch does not turn freely. I have checked that it has been assembled properly, thin thrust washer between gear and rotor, chamfered washer correctly orientated towards engine. How common is wear on the thin thrust washer and does anyone have the thickness it should be.
What else could be the problem.

Cheers Rob

Kz1000A1 / 2 / 3 / 4

Clearance between starter gear thin part (where the holes are)and the machined surface on the cases.
Clearance ................ Damper part number ..............ID Mark
5.06 to 6.05 mm .............. 92075-192....................... *
6.06 to 7.05 mm .............. 92075-193....................... **
7.06 to 8.05 mm .............. 92075-194....................... ***

The thrust washer doesn't control this it is the rotor taper / crank taper that does. If you have cleaned these up then it will reduce the clearance and you will have to reduce the damper thickness and maybe the thrust washer thickness as well. To measure press the rotor on by hand do not tighten up. Leave the damper rubber out and check thrust washer isn't binding.

Cheers for the info, should of said the engine is a Z1000J1, the basics should be the same though.

Cheers Rob

I have checked it with the damper off and it is binding between the clutch starter gear and the rotor, when the bolt is tightened up. I presume that the thrust washer is worn.
The engine I got did not have the rotor with it, so could that be a problem , although there is no difference between the rotors through the model range.
The taper on the crank looks fine, I will get a new thrust washer, just in case it is worn (thickness 0.97mm).
Cheers Rob

I would expect the thrust washer is too thick not worn. Wear would increase the clearance, do you have the right rotor / thrust washer in or has the previous owner cleaned the tapers up before. Leave it out and check the free movement of the gear.
Kawa 1000 / 1100 manual:

"6.3mm * 92075-1129
7.3mm ** 92075-1130
8.3mm *** 92075-1131

the std rubber is 7.3mm thick and the starter clutch should be rotated by hand with slight drag felt. If the starter gear turns freely without drag replace the rubber damper with the next thicker size, if it cannot be rotated or heavy drag is felt replace with next thinner one."
Unfortunately it doesn't give thickness of thrust washer

just to throw something else in the mix and possibly hi jack the thread, but when i use my starter the engine starts fine but sounds like the whole starter system continues to spin for a couple of seconds after the engine has fired up

Hello Mikey, i`m glad you asked that one because exactly the same is happening with mine. I`m guessing that if others are having problems with the cup causing drag, then maybe if it`s too worn and doesn`t have any drag the ring gear then spins freely.
My starter clutch was slipping badly before, i then took it apart and found the 3 bolts holding the sprag clutch were loose. I re-torqued those with threadlock, and also put bearing loctite (641) on the crank taper (after using some valve grinding paste to clean it up) to stop that spinning, and put it all back together. Now it starts great, but i get that whizzing sound when you turn the engine off from something still spinning, is it safe to leave it like that?
Fecking annoying when it`s a total bastard to get the main bolt out, what do you guys use to lock the crank when undoing/doing up the main bolt? A bit of wood jammed in the rear wheel against the swingarm seems a bit yeehah, especially when you hear the wood starting to crack! Oh yeah and i also had to use a hot air gun at 600 deg, to soften the loctite i`d put on the taper previously to stop the starter clutch from spinning!
Also sorry for this slight hi-jack, but it`s all related and is all usefull info! So thanks in advance.

I have tried it with and without the damper fitted, as the starter clutch is rubbing on the rotor, surely having a larger shim in between them will add more clearance as the starter clutch face rests on the shim. .
I have also tried it with and without the shim, still no difference.
I will have to speak to Jack about the parts as the rotor did not come with the engine.

Rob

AndyZ1R wrote:Hello Mikey, i`m glad you asked that one because exactly the same is happening with mine. I`m guessing that if others are having problems with the cup causing drag, then maybe if it`s too worn and doesn`t have any drag the ring gear then spins freely.
My starter clutch was slipping badly before, i then took it apart and found the 3 bolts holding the sprag clutch were loose. I re-torqued those with threadlock, and also put bearing loctite (641) on the crank taper (after using some valve grinding paste to clean it up) to stop that spinning, and put it all back together. Now it starts great, but i get that whizzing sound when you turn the engine off from something still spinning, is it safe to leave it like that?
Fecking annoying when it`s a total bastard to get the main bolt out, what do you guys use to lock the crank when undoing/doing up the main bolt? A bit of wood jammed in the rear wheel against the swingarm seems a bit yeehah, especially when you hear the wood starting to crack! Oh yeah and i also had to use a hot air gun at 600 deg, to soften the loctite i`d put on the taper previously to stop the starter clutch from spinning!
Also sorry for this slight hi-jack, but it`s all related and is all usefull info! So thanks in advance.

This seems such a common problem you'd think there would be a solution by now. As far as what I do when I tighten up the bolt is concerned, all I do is put it in fifth and get someone to stand on the rear brake. That said the feeble bolt on the A1 is only torqued to 18 ft lb.

I've measure the clearance using a lump of hard putty against the crank inner race and my clearance is perfect for the ** damper rubber currently installed. I'm thinking this set up was simply not designed for high comp engines (Wiseco).

After having no real joy with the replacement rotor from Z Power I'm going to go down the road of replacing all the shims and needle roller etc with new, lapping in the rotor and using stud lock.

I've never tried this before so who knows

This information could be helpful but I'm not exactly sure what the poster is referring too.

http://www.z1ownersclub.co.uk/forum/vie ... php?t=8611

Sorry, I didn't see this post earlier - it's quite likely that the bolt's not looseing and letting the rotor slip, it's the other way round. The rotor's breaking off the taper and snapping the key, spinning and loosening the bolt. The key really only positions it, it's too flimsy to do anything else that's why they did away with it and the bolt just secures it, it's the fit on the taper that should really hold it on. If it keeps coming off it's because the starter clutch is worn on the boss on the big sprocket at the back - it doesn't have to be really even visible - then the rollers catch and snap it off the taper. It is more of a problem with high compression because starting a high comp motor tends to wear the starter clutch more so this is more likely to happen. Try and get a new complete starter clutch it should fix it. I had the same problem about eight years ago - hasn't happened since.

My black Z1000 had this problem..... When I got the bike she would make a rumbling/rattly noise on low revs/idling

I put it down as clutch rattle for a few 100 miles

Eventually I removed the alternator cover... The 3 x allen screws where loose... Luckily there was only slight damage to the soft rotor body & I loctited them back in OK - That was a couple of years back.

Since them, no problems (touch wood ). Oh yeah, and its a 1075 Wiseco hi-comp, gas flowed with RS 36's

To hold the rotor still whilst tightening the bolt, I used a nylon "tie strap", wrapped it tightly around the rotor & tied it to the foot rest Worked a treat, coz it holds the rotor without damaging anything, & none of the transmission slack & 'torque' to deal with if you try & whack a bit of wood in the rear wheel

"I have tried it with and without the damper fitted, as the starter clutch is rubbing on the rotor, surely having a larger shim in between them will add more clearance as the starter clutch face rests on the shim"

The starter gear slides into the clutch which mounts on the rotor with a spacer in between the clutch rollers and the rotor. The mounting point for the rotor is the crank taper. On Mk2 there are two thrust washers controlling the lateral movement of the starter gear, one in the clutch and one which spaces the damping rubber. These are thrust washers. the only reason they will bind is of there is not enough clearance ie if the rotor has moved towards the crankcase face. The only way that happens is if you have the wrong rotor or if the crank / rotor taper has been altered from original. The points of reference are the crankcase face and the taper.

1 Are you sure the rotor / crank are correct? are the thrust washers in the right way round?

2 Remover the damper rubber, the starter clutch rollers and springs and try rotating the gear - it should move freely both ways.