Magnet adhesive

[mikew8760]

Thanks to all who have added their 2 cents worth to this thread.
I have obtained a clutch from the greenbike people and will fit it when time permits. However, my curiosity forced me to examine the old one. I expected to find worn rollers, broken springs and such-like, but I was disappointed to find nothing obviously amiss! Of course, the proof lies in the motor's behaviour with a new clutch, but I'm worried that having apparently ruled out everything else there is still something I've missed. The only part that looks a bit worn is the tiny ( Woodruffe) key that fits in the drive shaft, and some odd burring of the shaft close to the slot. But I cannot believe that would cause the clutch to slip.
Any ideas folks?

 

[Woosh]

But I cannot believe that would cause the clutch to slip.

inside the clutch, there is a one way bearing made up with needles.
The needles do get worn in time.

it looks like this:

 

[mikew8760]

Thanks Mr Woosh. Attached is a photo of the "working" part of the possibly defective clutch (with the grease cleaned out). As you can see (and no doubt are quite aware) this one has 3 rollers. Close inspection doesn't show any uneven wear, flat spots, surface pitting etc of any part, so maybe it wasn't the culprit?
The only thing is a small high spot on the uppermost roller and a corresponding wear witness on the cover plate. But, as before, I don't think this would cause problems, although it would indicate that this roller may have been 'sticking'.
No doubt all will be resolved when I've got it all back together and hit the road!

 

[Woosh]

try turning the innermost ring, it will turn freely in one direction and engage the planet gears in the opposite direction.
The transfer between the innermost sleeve (where the woodruff key goes) to the outer sleeve is where the slip occurs.

 

[mikew8760]

After a fairly long break due to weather and other interruptions, I finally got to try out the motor with the new clutch flitted. But, as I feared, it has made absolutely no difference; the staccato rattle is still there under some load conditions. Sadly, it's the result I was expecting, as I dismantled the old clutch and could find nothing wrong with the mechanism. Grrrrrrr!!
The only 'fault' I could find is that the clutch is not firmly fixed to the shaft. The puny key that transfers the drive to the clutch is slightly loose in the keyway, since over time it and has worn and also one shoulder on the shaft, the one that bears all the force. The movement is slight, but I suspect that this looseness allows resonation with the impulse forces of the phase drives. In my view, the drive chain should/must be solid throughout. I'm a little surprised at this 'design' and would have expected a 'proper' Woodruff key, possibly of the tapered type which allows any backlash to be eliminated. The key in place is a small (8mm x 5mm x 5mm) rectangular steel block.
I wonder if anyone has any experience of this design and may confirm or refute my idea, or suggest a remedy. As things stand I'm now competely fed up with the thing and considering shelling out for a brand new motor!!