'82 XJ650 - Help with clutch troubleshooting

I've never had any trouble with clutches before so I'm not positive on what's the best course of action. Here are the facts:

1. Previous owner replaced the friction discs and the clutch basket/hub after cracking the hub during the reassembly. I have the old parts in a box. I don't know how he cracked the hub or why he had the clutch apart in the first place.

2. Clutch operates beautifully when engine is "cold". Problems only appear after riding a mile or two.

3. The clutch drags at all speeds. To put a band-aid on the problem I adjusted the clutch cable too tight to take some pressure off. I am aware this is not correct. Before I did this the bike stalled at stops and I needed to practically kick the shifter to change gears. Finding neutral with the engine running was not possible. #3 through #5 are what occur after I did this quick "fix".

3. Clutch drags at seemingly random times. For example, I stop at a traffic light and the engine speed gets "pulled down" to a low idle. At the next traffic light I pull the clutch in and the engine idles high. I haven't found any pattern to this symptom.

4. The bike lurches when the clutch is 'eased out'. This is best described from the perspective on 1st gear from a stop. Rev a little, ease the clutch out, found the friction zone, hold, hold, speed is good, ease the lever out, lurch, release the lever, ride away. This happens whenever the clutch is eased out whether from a stop or between gears. A quick in-and-out between gears does not produce a lurching sensation.

5. Clutch slips under excessive power. Sometimes it's very obvious and sometimes I wonder if I'm running lean (different problem). Clutch will slip for several seconds before the bike lurches and the clutch no longer slips.

My gut tells me that the drive plates are warped but I haven't taken anything apart yet. What do you think?

 

I think you need to take it apart and investigate. The steels could be warped; the pressure plate may not be properly oriented to the hub; the "wafer" bearing could be disintegrating; the basket or hub may be horribly worn; there are many possibilities.

 

Yeah that seems reasonable. Not one hour after I posted this another chunk of primary chain guide wedged itself in just the right spot. Looks like I'm going to get a good look at the inside of the engine sooner than I thought!

For the sake of shits and giggles I adjusted the clutch properly this time to ~1mm slack at the bowden cable sheath and took it up and down the road. The clutch drug but no worse than usual, plus the lurching was gone! What the heck, clutch?

 

What is the condition of your cable? Frayed? Lubricated? Can you put your bike details in your profile please. Has this clutch ever worked properly since you first bought it?

 

The clutch cable is in good shape. The clutch has shown the above symptoms since the day I bought it.

 

The changing symptoms indicate either a cable going bad (broken strands inside, allowing differing degrees of stretch rather than activating the clutch properly) OR there is something seriously amiss in the clutch itself. Remove the cable, flush it out, and properly lubricate. Then ensure the inner cable slides smoothly and freely within the sheath. If not, replace the cable.

Access to the clutch is simply a matter of removing the cover; it doesn't require any "major surgery" like changing the chain guide will.

I'd suggest immediately addressing the clutch issue; you can put off the chain guide for a while as long as you don't mind picking hunks of plastic out of the shifter forks occasionally.

 

I contacted the previous owner and was told that he replaced the clutch cable while he was replacing clutch parts.

I got a good look at the clutch while taking apart the engine and I found a few things out of the ordinary:

1. The drive plates look "polished" as if they were run with no oil. Some more than others but they all had rings around them.

2. There seems to be small metal flakes in some of the friction plates. I don't know if they actually are metal flakes as they seem to be deeply embedded but the surfaces are smooth. I'm not sure if these are just "light spots" and are normal or they really are metal and are going to be a problem.

I'm going to replace the drive plates with the old plates from the "obligatory box of spare parts" that came with the bike as those do not have any signs of polishing. I'm also going to readjust the entire clutch system from rod to perch. Between these two actions and some luck I'm hoping my problems go away.

 

The problems went away after putting the first set's drive plates in with the second set's friction plates. However, after two months the problems are coming back. I expected as much but it just means it's time for a new kit. Unlike the previous owner I don't think I'm going to settle for the cheapest one on the market.

 

Notice on the basket if the friction plates have worn gruves in it.
Get the parts from Chacal and they'll be right.
Get springs too, old springs will let it slip with new plates.
You don't need bolts, you do need a small torque wrench.