'81, all stock clutch. No problems riding, seems completely normal. But...today I was on the top of a hill and for fun I thought I'd coast down it and pop the clutch to start the bike. Popped it in 2nd and couldn't feel the engine turning, or even a jolt. Pulled in the clutch and put it in 1st, and tried it again. Same thing. Did recently switch to GTX 20w50 when I couldn't find my regular brand. And again, riding seems normal. Had the engine apart a couple years ago and didn't measure the plates but didn't notice anything unusual about them.
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unusual slipping clutch?
- Thread starter xjwmx
- Start date
Yeah, it's slipping. The high primary ratio 'tween the clutch and engine puts a big demand on the clutch. With a good clutch, and a stubborn engine, expect the rear wheel to slide...
Yeah something seems very odd. Were you in gear, clutch in going down the hill? Or in neutral? Slamming into a gear engine stopped when moving is usually a significant event.....
Pretty sure it was in gear both times I popped the clutch. I'll try again just to confirm. You never know.
If the plate thickness is still good, is it safe to assume the problem is this oil, and will scrubbing them with gas fix them? Looks like new fiber rings are around $80 but of course would rather not spend if don't have to.
Yes, I know it's usually a "significant event." Once I had fouled plugs from swelled needle valve tips, and as a last resort to start it popped the clutch on a hill that was wet.... started but was angled at 45 degrees for a bit.
If the plate thickness is still good, is it safe to assume the problem is this oil, and will scrubbing them with gas fix them? Looks like new fiber rings are around $80 but of course would rather not spend if don't have to.
Yes, I know it's usually a "significant event." Once I had fouled plugs from swelled needle valve tips, and as a last resort to start it popped the clutch on a hill that was wet.... started but was angled at 45 degrees for a bit.
jussumguy
XS650 Addict
I know oil is cheaper and easier and you might as well try it first, but the springs are 40 years old now. Might have to switch them out if bump starting is important to you. Does the clutch slip when you’re on the gas?
Its like trying to bump start in too lower gear, try 3rd or 4th gear and you will be ok.
That's interesting what you said there signal, cause at one point in the colder weather and a loose fuse,my bike would stall and if I tried to get it back going in the higher gears, no go, in 2nd it would turn the motor and get back going. It's like each bike has its own way and like certain oils, I think that's part of the mojo of our xs650s and this forum,
Ok double checked the actuator adj, was not a problem, and tried it again on a faster hill, about 35 mph, and it would bump start in 2nd. But still felt about the same as far as shock of engine engaging goes.
Also, realized it will roll pretty easily in 2nd with the engine off, which I didn't expect. Could seem to feel the engine turning over though. 150 lbs last time I checked.
Also, realized it will roll pretty easily in 2nd with the engine off, which I didn't expect. Could seem to feel the engine turning over though. 150 lbs last time I checked.
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Kickstarting goes thru 1st gear, and the clutch. Same clutch demand as your bump-start in gear. With one exception.
With kickstarting, the clutch has been engaged for awhile, and oil between the plates has been squeezed out.
With bump-starting, the clutch starts out disengaged, the inner hub and steel plates are spinning as the bike is rolling. The basket is not spinning. The steel plates would be picking up oil, keeping a thin film. Then, when the clutch is dumped (engaging), it must shed that oil film.
On a running engine, the basket is spinning, and will centrifugally shed oil.
That would make the oil the only suspect?
I suppose an experiment would be to pull-in (disengage) the clutch, start kickstarting, and while kickstarting, slowly let out (engage) the clutch. Get a feel for how it slips as it becomes engaged...
With kickstarting, the clutch has been engaged for awhile, and oil between the plates has been squeezed out.
With bump-starting, the clutch starts out disengaged, the inner hub and steel plates are spinning as the bike is rolling. The basket is not spinning. The steel plates would be picking up oil, keeping a thin film. Then, when the clutch is dumped (engaging), it must shed that oil film.
On a running engine, the basket is spinning, and will centrifugally shed oil.
That would make the oil the only suspect?
I suppose an experiment would be to pull-in (disengage) the clutch, start kickstarting, and while kickstarting, slowly let out (engage) the clutch. Get a feel for how it slips as it becomes engaged...
That's a good idea. Just to be clear, there's no trouble kick starting, and the bump start yesterday was just for fun, but led to this discovery.
The time I mentioned when kicking wouldn't work and I could only bump start it was because it needed that much cranking because the plugs were so crap.
The time I mentioned when kicking wouldn't work and I could only bump start it was because it needed that much cranking because the plugs were so crap.
I bump into things occasionally while researching, and one that caught my eye was the experiments and improvements in motor oil "thin film lubrication" and "film strength". Welcomed improvements, but not so sure with our clutches.
Never ran into clutch problems back then as prolific as our forum's current crop of issues...
Never ran into clutch problems back then as prolific as our forum's current crop of issues...
I did the experiment. Only notable thing was first try with clutch pulled, kicker was still sticking hard from surface tension or something.
I think I'm going to switch to some mc-specific that walmart carries, or perhaps vr1, though they're the same price. Not burning any oil at all now, so makes more sense to spend on oil. Next time right cover is off going to check plate thickness, and maybe do springs regardless. Springs are cheap. Maybe too cheap...
Those grooves in the fiber clutch rings, are they meant to serve as wear indicators? In addition probably making the plates separate easier.
Also, why is there only like a few thousandths wear allowed on those rings -- surface? Can they be easily home resurfaced somehow?
I think I'm going to switch to some mc-specific that walmart carries, or perhaps vr1, though they're the same price. Not burning any oil at all now, so makes more sense to spend on oil. Next time right cover is off going to check plate thickness, and maybe do springs regardless. Springs are cheap. Maybe too cheap...
Those grooves in the fiber clutch rings, are they meant to serve as wear indicators? In addition probably making the plates separate easier.
Also, why is there only like a few thousandths wear allowed on those rings -- surface? Can they be easily home resurfaced somehow?
If/when you pull the clutch, feel the fibre plates, see if they feel sticky, like post-it notes.
The grooves are to allow oil to pass thru, to remove grunge and heat. Otherwise, the clutch would overheat, and the hub would just fill up with oil. They also help to scrub/squeegee oil off during engagement. Some interesting groove designs out there, to help with separation.
Post #43.
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/page-3#post-479151
The wear limit has a lot to do with the "total stackup thickness", best kept in the range of 29-29.4mm for the 70-79 clutches. Don't have the figure for the final 80-83 clutch. The pressure plate has a narrow region of function. If the stackup thickness is low, you risk having the pressure plate settling atop the hub, and not squeezing the plates. Too thick and the clutch springs get too compressed, may enter coilbind during disengagement, and the pressure plate may uncouple from the hub's splines, or worse, *bonk* into the sidecover.
You *can* refreshen the frictions. Clean, and do a light lapping with something like #320 grit on a flat plate, similar to the steel plate lapping shown in this post #89.
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/page-5#post-503293
The grooves are to allow oil to pass thru, to remove grunge and heat. Otherwise, the clutch would overheat, and the hub would just fill up with oil. They also help to scrub/squeegee oil off during engagement. Some interesting groove designs out there, to help with separation.
Post #43.
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/page-3#post-479151
The wear limit has a lot to do with the "total stackup thickness", best kept in the range of 29-29.4mm for the 70-79 clutches. Don't have the figure for the final 80-83 clutch. The pressure plate has a narrow region of function. If the stackup thickness is low, you risk having the pressure plate settling atop the hub, and not squeezing the plates. Too thick and the clutch springs get too compressed, may enter coilbind during disengagement, and the pressure plate may uncouple from the hub's splines, or worse, *bonk* into the sidecover.
You *can* refreshen the frictions. Clean, and do a light lapping with something like #320 grit on a flat plate, similar to the steel plate lapping shown in this post #89.
http://www.xs650.com/threads/yamaha-xs650-experimental-clutch.47498/page-5#post-503293
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I was at wally today buying groceries and noticed they sell mc-specific conventional Valvoline 20w50 for a little less than $5. That's my new oil I guess, if they keep it stocked -- there was just two cans left. If so, no conceivable reason to use something else.
When I switched to Valvoline conventional 20w50, my cold oil pressures went up.
Maybe a good thing.
Post #66.
http://www.xs650.com/threads/hp-oil-pump-from-mikes.40991/page-4#post-482782
Maybe a good thing.
Post #66.
http://www.xs650.com/threads/hp-oil-pump-from-mikes.40991/page-4#post-482782
Been using Valvoline VR1 20-50 in all my bikes for a while now, Has ZDDP, no clutch issues on any.
