250SL clutch slipping mystery

[Darrell]

Hi all,

A previously well performing 250SL clutch is now slipping right after a complete engine teardown and reassembly.
The freeplay adjustments at the actuating arm and lever are to spec.

Before I take off the side cover (I hate doing that because there's always a fight with the kick lever) what do you think I should be looking for??

I should also mention that I torqued the clutch nut to 35 ft lbs, and I'm a longtime user of Castrol Hypoy C gear oil (non-synthetic).

[Darrell]

OK. Nobody weighed in on this problem but I figured it out anyway.

During the engine reassembly I used a new sidecover gasket. Looking more carefully I realized the new gasket is much thinner than the one it replaced.

Using the same number and thickness of clutch disc spacer rings as before caused the actuator housing to slightly compress the clutch sufficently to cause some slippage.

This time, and in the future, I'm going to follow this simple procedure to determine the thickness and quantity of clutch disc spacers to use:

1.With the acuator piece in place rotate the clutch arm until the actuator face is flush with its housing using a straight edge or any flat piece of metal.

2. Holding this position, trace or scribe the angle of the clutch arm onto the sidecover.

3. After you install the clutch disc spacers and tighten down the side cover then the arm should be able to move several degrees further past your marked angle. The few additional degrees of rotation should indicate there's a bit of freeplay and the clutch is completely disengaged and ready to perform finer adjustments with the cable.

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Now I've got to start a new thread to ask what's causing my Wombat 94 to 4-stroke anywhere above one quarter throttle. This is an unpredictable and frustration bike that will run perfectly one day and lousy the next, etc..

[matt glascock]

Interesting. I had a similar problem after changing the clutch pinion bushing on my 94. The original was ever so slightly mushroomed and there were 3 spacers over the basket. After reassembly there was no free play in the actuating arm. With the proper bushing height and the spacers, this set-up "predisengaged" the clutch. Amazing how tight the tolerances are in that system. I'm rebuilding a 95CW. I'll try out your suggestion. Good call!