Clutch adjustment questions

B

bigbutterbean

Active Member
I'm not sure where to post this, so if its in the wrong place, feel free to move it mods. Ok, so here goes.

I noticed the other day that my clutch was a little loose, and for a temporary adjustment, I adjusted the tension on my cable by moving the barrel adjuster out a little. But I want to adjust it more properly, as the engine is a year and a half old, and I havent made any adjustments to the clutch in quite some time. So I have a few questions that I hope will give me a more detailed understanding of proper clutch adjustment.

I believe that my clutch pads may be a bit worn, and that is the reason for my clutch being loose. I know I can make the cable tighter, but since the pads are worn, should the clutch plate be brought closer to the pads? to do this, do I turn the flower nut clockwise, or counter clockwise (I think I know the answer to this, but want to be sure)?

The bolt that goes down into the crankcase that has a hole through which the clutch cable is routed, will moving it have any effect on clutch adjustment/operation? If so, should I tighten it (further into the crankcase) or loosen it (further out) to put more tension on the clutch spring? Will doing so make the clutch grab harder at lower rpms at all? Sorry for the newb-ish questions, I just want to make the best adjustments possible to my clutch for trouble free riding.
 
Adjusting the cable should only affect the free play in the cable- the distance of lever pull that takes up the cable slack until actual clutch operation begins. This also is used to adjust the "feel" of the lever.

Adjusting the flower nut ideally only adjusts how far the pressure plate moves away from the friction pads when the lever is pulled in and the clutch is disengaged.
On a new engine it is commonly misused to adjust the pressure exerted against the friction pads, This only has a real effect when the flower nut is initially way out of adjustment. Adjusting the flower nut closer to the pressure plate does have a limited effect on increasing the overall pressure applied to the friction pads.

In your situation the friction pads most likely have significant wear and adjusting the flower nut should be considered normal clutch tuning to compensate for normal wear and tear.

The only way to significantly adjust the pressure exerted against the friction pads by the pressure plate when the clutch is engaged is by tightening up the adjustable spring retaining ring which is located internally.
See this thread written by Norman for more info: adjusting the clutchs spring for more tension
 
Bean,
What do you mean by "my clutch is loose"? Is it slipping? Engine over reving but not pulling? Or are you saying the clutch actuator arm is sloppy, loose in the cover?

Tom
 
Hmm, good question, Tom. Sorry I wasnt clear. I have to pull the clutch arm the whole way into the handlebar for the engine to idle. If I just pull it in and lock it in place, its kinda half in gear and kinda half not in gear. As I said, for the moment I have adjusted tension on the cable via the barrel adjuster. Whenever this storm passes (hurricane Sandy), I am gonna adjust the tension on the clutch spring using Norm's method.
 
Bean,
If the clutch isn't slipping and what you describe is the only problem I still lean toward cable tension. The clutch cable can/will stretch over time and there's also wear on the clutch actuating mechanism such as the cam inside the cover, the bucking bar or pin and the bearing. Wear in any or all of those will decrease the effectivness of the cable's ability to disengage the clutch.
Some builders like a little slack in the cable, I prefer none. I don't make them bow string tight but there's little to no slack from the end of the cable to the clutch actuator arm at the engine end.

Also you might be seeing wear in the handlebar lever. That can account for it not disengaging completely when in the locked position.
Good luck with the storm and stay safe.

Tom
 
Yeah, I just feel its time to make some proper adjustments for better clutch life and operation. Thinking that perhaps adjusting the tension on the clutch spring will reduce wear on the pads. And since I haven't made any real clutch adjustments on this engine yet, might as well get it all done at once.
 
if the clutch is not slipping while you are riding down the road in any condition, especially under a strong load such as climbing up a hill, then there really is no reason to tighten up on the main clutch spring. Do bear in mind that the stronger the main spring pressure is, the harder all the release components have to work against it to dis-engage the clutch.
If you are striving for a longer component life, then this is backwards from your overall goal.
That said, if the clutch is actually slipping and there is nothing else mis-adjusted with the cable tension or flower nut, then tighten up the main spring a little bit.

I gotta agree with 2door though. It sounds like the cable is too slack or the hand lever pivot has become very worn. If it is the hand lever, fix what is the actual problem...replace the hand lever before trying to band-aid the problem by fiddling with the other clutch components.
The other thing it could be is the clutch cable itself. Not only do they stretch with use, but they can also get slightly elastic. They can act sorta like a rubber band. This is due to the way the individual wires are wound during the cable manufacturing. As the cable stretches and wears over time they unwind a little when taught and recoil themselves when slack. It is an anomaly I find hard to believe, but I have experienced the difference between a new cable and an old, worn cable on a racing clutch (read stupid strong multiple clutch springs) setup myself so I cannot dispute it.
 
Well, I changed my mind about adjusting the tension on the clutch spring. I would have had to take my carb and my intake off to get at the spot where the spring retaining nut is, and I didnt have time to do that today. The bike was in the basement, and I needed to get it out of the basement today, so I fixed my clutch cable and called it good. The clutch wasn't slipping before, I was just hoping that putting more tension on the spring would help it grab better at low rpms, but alas, I had not the time or patience to go through with it. So, the clutch cable is fixed and tightened properly, and the bike is chained in its usual spot in front of my house.
 
But, how does it feel now? Unchain that rascal and let us know what adjusting the cable tension did for you.

Tom
 
So I thought I would give an update. So I have noticed lately that even when I would choke the engine (getting colder here in PA), it would sometimes take awhile for the engine to warm up and run smoothly. Also, I would sometimes have to flip the killswitch more than once to kill the engine. After thinking on things for awhile, I surmised that the clutch wasnt disengaging completely. When I fixed my clutch cable, I know that I had proper tension on it. So I thought about adjusting the flower nut to see if that would resolve the issue. I removed the cover and with the clutch lever locked in place, I pushed on the clutch plate to see if it moved at all. It did not. My clutch plate was right up against the pads. I loosened the flower nut a quarter turn, and it fixed it right up. I took the bike around the corner, dumped the clutch, and she kicked over IMMEDIATELY and ran smoothly, no jerking, no taking off and slowing down about six times till she would stay running, like she did before I loosened the flower nut. She idles smoothly, and I only need to flip the killswitch once and the engine dies. So I dont think the cable was ever the problem, though I am glad I fixed the cable anyway. I believe the flower nut adjustment was the issue the entire time.
 
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