Clutch stops working in heavy traffic.

Hi everyone,
So here's a problem i encountered about 2-3 times already with my Yamaha XJ 600N '01.
I rode in heavy traffic, with warm/hot weather outside (about 27C / 80 F), it all happened after about an hour of riding. When going real slow and shifting for quite a few minutes only between N and 1st gear the bike started to slowly move forward with clutch handle fully pressed (in 1st gear), then the revs begun going down, it stared to shake a bit (like being in a friction zone) and then the engine stalled completely! Fired it back on, i couldn't change gear at all (i was still holding the clutch as hard as it gets), then again revs going down, a bit of shaking and engine shuts down. I was able to go back home when i stayed at the place for about 30-40 min and the bike cooled off a bit. For next 20 minutes i was able to change gears normally and got home.

Wen't to a repair shop. They inspected the clutch, and said it's almost dead. They replaced friction plates (supposed to be quite worn-out, springs (didn't hold the parameters) and replaced a clucth cable (it was seriously bent in one place).

But after getting it back i've had the exact same problem when after an hour of riding i got into heavy traffic.

What can be wrong here? Is the engine overheating?

 

The clutch is dragging from what you state, in other words not fully disengaging. They should have replaced the clutch cable and adjusted it properly then tried the bike before replacing the clutch. Did they give you the old parts so you can check them for spring length and friction disc thickness?

 

No, i don't have these parts, but more like i didn't take them. They showed me what the parts looked like, but i'm nowhere near an expert, so figured there's no need to take 'em with me.

 

You can check the friction disc service limit and the spring length service limit to see if they are in spec so you know for next time.

 

Yeah, probably, that's a nice tip, thanks.
But i'm still stuck on that mysterious problem anyway. If the clutch has been replaced what else could it be?

 

Not trying to be unhelpful but you should take it back to the shop that did the repair. As it is still not right it looks like they have not adjusted the clutch cable properly. If the clutch is not fully releasing when you pull the clutch lever fully back to the handlebar the bike will move forward. The arm on the clutch case has to be correctly positioned, and the clutch cable adjusted so that it is fully engaged (friction plates and steel plates locked together) when the lever is fully released and they are apart when you have the lever pulled against the handlebar grip. You should get a Haynes manual if you do not have one.

 

The intriguing part about it is that it works perfectly fine until i get into heavy traffic with multiple stops. And after cooling down it works again, i can shift then and all that.
They told me that if anything goes wrong after clutch replacement (i suspect the cable was adjusted) it has to be something within the engine or gearbox, which means taking it apart, which means fixing other possible issues, which might get very expensive very fast.

 

so , XJ600n ,01, is the water cooled diversion model "right" so you ask is it overheating, my guess would be Yes.
when in traffic ,can you hear the fan starting up, if you run it at standstill does the fan start, that could be the problem

 

This should be oil-cooled, not water-cooled, I think. So no fan...

While it's possible that the new clutch itself is having issues, I agree with Franz that it sounds more like it's out of adjustment than anything else. When hot, the clearances inside the engine case will change. While the adjustment may be just barely OK when at cold to moderate temps, the lever may not be applying enough pressure when not to fully disengage the clutch when hot.

I would see if you can tighten up the clutch cable just a hair. There should be an adjustment at the lever - loosen the lock nut, then turn the larger knurled knob so that it moves the cable out away from the lever - I'd make small changes, maybe 1/2 of a turn at a time. After each adjustment, ensure that the clutch does not slip when applying thottle, if it does, you went too far. Also as Franz alluded to, see that where the cable attaches to the actuating arm down at the engine case, the cable should be at approx a 90* angle. See https://www.motorcycle.com/how-to/basic-maintenance-how-to-adjust-a-clutch-cable for the basic process.

You *shouldn't* have to adjust the cable down at the case unless you've run out of adjustment up at the lever; generally the lever is considered a 'fine' adjustment and the case is considered a 'course' adjustment.

Just to be certain, this is a cable operated clutch, not a hydraulic clutch, right? And, have you had any problems with the clutch slipping under power (lever fully out, give it full throttle and the revs climb without the bike accelerating accordingly)?

EDIT to add that if your bike has been fitted with adjustable levers, and you're pulling the clutch lever in enough to make contact with the handlebar, you may need to adjust the lever out away from the bar a stop or two to ensure you have enough throw to fully disengage the clutch.

 

Well you were both right here - amazing. I couldn't believe this might have been the case since they replaced the clutch cable and put new levers for me, so i wouldn't even imagine they would not adjust the cable right.
I took it to another mechanic which turned out to be a blessing. In the previous shop (where they replaced the clutch) seems like they didn't know what to do or didn't care much, who knows. They suggested gearbox problems afterwards!
The cable was working fine until the engine got hot and the clutch was used frequently (like going through the city center with multiple stops at red lights). The cable was supposed to get slightly longer due to temperature and that already wasn't good enough to pull the mechanism to disengage. A bit of adjustment of the cable at the levers and of the lever itself fixed the whole thing.

 

Gearboxes rarely give trouble. Good you have it fixed.

 

Well, the cable length won't change with riding in town, but the thickness of the clutch plates will, and there are quite a few...
My experience with old Yamahas suggest the clutches are close to the limit between slipping and not disconnecting drive. Maybe it's just me..
Certainly though, the choice of clutch cables doesn't help, some of them are pure rubbish, in that there is too much "give" in them...