More clutch slip

I've got a 78 kz650 that i bought recently. I've been working on it for the past two months and just got it running again today. When i rode it around town the clutch was working just fine, but is progressivly getting worse!! By the time i got home, it would barely work. If i gave the bike even moderate throttle it would just rev, and not go. It ran fine when i parked it. I just did an oil change. I put valvoline 10x40w 4stroke motorcycle oil in it... should i have put something different? I'm afraid that is what caused it. The clutch is very hard to pull though, and i don't remember it being that hard eariler. The lever is releasing all the way, so i would imagine the cable isn't binding. Any ideas anyone? Thanks!

ive never had a problem with valvoline oil and wet clutch.id say try adjusting it first but if its slipping that bad it might bea good time to check your clutch plates and springs.if you are going for a basic cruise around town type of bike a stock style replacement clutch should be up to the job.

As wireman says try adjusting clutch.

This would include cable adjustment at clutch lever and any mid-cable adjuster. And also adjusting the clutch push rod under the access plate on the engine sprocket cover. There's a lock nut to loosen, then a screw to turn in until it stops and then back the screw out 1/2 turn, then tighten the lock nut.

Am wondering if the clutch push rod adjustment is too tight and thereby preventing the clutch plates from completely closing together when the clutch is engaged -- in other words, causing the clutch to slip.

When pushed in, the clutch push rod spreads the clutch plates apart to disengage the clutch. The 1/2 turn out provides free play allowing the clutch plates to completely engage with no pressure on the rod. Without the free play, the clutch will likely slip.


Post edited by: Patton, at: 2007/03/07 23:51

I lubed up the cable and re-routed part of it where i thought it might be hanging up. I also let out some of the slack and it seems to be doing better. I could get on it after a good 20 minutes of driving with no real noticable slip. It still engauges farther out on the lever when its warm than when its cold though :S Can anyone explain why that would happen??

So long as there's a little cable slack, increasing slack doesn't affect clutch rod adjustment and won't correct a too tight clutch rod adjustment.

For example, completely removing the clutch cable will not correct a too tight clutch rod adjustment and the clutch will continue slipping.

However, if the plates are worn out, the clutch will slip regardless of adjustments.

Hope it's the simple easy fix of a clutch rod adjustment.

You said that it got worse on just a short ride and that it pulled harder than you remember, sounds like it might be the pushrod cam assmebly is dirty, worn, or broken causing the internal workings to jam and drag. Just a thought, good luck.

bdecho wrote:

. . . It . . .engauges farther out on the lever when its warm than when its cold though :S Can anyone explain why that would happen??

I can try. . .it's likely the engine heat is expanding the metal plates in the clutch, making the entire assembly more tightly bound. Lever use would activate the slip point sooner. Just an opinion. How many miles do you have on this vehicle?