Kawasaki Motorcycle Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Rebuilt Clutch on 87 Ninja 750. Hydraulic clutch with slave cylinder.

I checked the push rod and it looked fine - but was hard to push back in. I had verified everything was operational before putting back together.

Initially worked fine - parked it - came back to ride - slipping VERY BAD.

I had already bled system and now thinking the push rod is not releasing all the way due to air in hydraulic line.

Any ideas on bleeding to release air trapped in system.

Next step would be to remove the slave cylinder.
 

·
Registered
Joined
·
3 Posts
zx7r New replacement clutch slips, bike goes nowhere!

According to the factory manual for the zx750p2, when replacing all plates the manual recommends 6 X 2.3mm steel plates and one 2.0mm,2.3mm,or 2.6mm plate. Then a free play measurement must be performed. Even though in the first section it recommends only the 2.0mm OR the 2.6mm, later it does state that it may be necessary to use a 2.3mm thickness for the seventh plate. This procedure is only used when replacing all friction plates.

So I had a free play measurement of .17mm with the seventh steel plate being 2.6mm, which is in tolerance with the usable range between .05mm -.35mm. However I noticed when tightening and torquing the spring plate, that the clutch would simply slip, making it impossible to torque without jamming the output sprocket.

Having started the motorcycle when selecting first gear the bike would shudder, then immediately was followed by a lesser shudder. So it felt as though the gear was engaged momentarily, but then the clutch would slip and give way. When letting the clutch out after putting the transmission in first gear, nothing happened, not even a vibration could be felt.

After fuming about it all night I have come up with two possible solutions to why this can happen. First, since the last friction plate on the stack is seated in an offset channel to the rest of the stack, it is possible that the 14 total plates do not go any further than this channel for the last friction plate. This would cause the spring plate to simply be pressing against the last friction plate, which in turn is completely seated in it's corresponding channel in the basket. So the spring plate is pressing on the friction plate which is only pressing on the basket, leaving space between the remaining 14 steel and friction plates.

The second, which is less probable than the first solution, is that the inner hub/cam is jammed or not properly seated.

One thing I am sure about is that the hydraulics used to disengage the clutch will have nothing to do with it slipping since there is an obvious non-equilibrium between the hydraulics and the mechanics of the clutch system. To test this, I removed the slave cylinder and I could still rotate the spring plate by hand while the transmission was in first gear.

I will know by tommorow what the problem was and share my findings with, since I know how frustrating this problem is.
 

·
Eddie Lawson is God!
Joined
·
5,683 Posts
But, mark has an OLD SCHOOL 1987 Ninja and does not have a slipper clutch, so anything you tell him will not be germane to his problem.

Disassemble and clean the slave cylinder, making sure you remove the congealed brake fluid from BEHIND all the seals.

Then take the master and make sure the glop is cleaned out of the reservoir. AND THE RELIEF PORT IS CLEAN. Fill and bleed just like a brake.
 

·
Registered
Joined
·
613 Posts
When you rebuilt your clutch did you replace the steel plates as well as the friction plates?

If your clutch line has too much pressure built up then it could cause the clutch to always be partially disengaged.

An improperly bled clutch line would cause the clutch to never disengage so you probably wouldn't be able to select gears.

Also, I would check and make sure that your not using a friction reducing oil.
 
1 - 5 of 5 Posts
Top