What can I do to the primary clutch to stop it from rattling at idle,? above Idle its quiet

electric saw or petrol driven
electric you have to pull the safety guard back to engage drive dogs
petrol driven is a centrifugal clutch that engages above idle and the safety bar is a brake on the clutch to stop it from turning
pushing the bar forward and then revving the engine will result in a burnt out clutch

Normally the pins and bushings get worn on the cams. You should replace them before they get too bad.

I don't know what your exact bike is, but all my bikes had clutch cables - they were not hydraulic actuated - which meant you could take up the "play" - the slack - as the cable stretched.
IF you have a clutch cable, there should be adjusters and jam nuts at each end of the cable.
Be careful not to take up too much slack!
P.S. your manual will have this under the 'maintenance' section.

You have a problem because a Harley rattles??? That is like saying you have a problem with English bikes leaking oil.

Does the noise happen only when you pull in on the clutch (disengage the clutch), and go away when you let the clutch out (engage the clutch)?

If so, that's the clutch plates rattling until the spring load is reapplied to clamp the up.

If you shift to neutral and release the clutch and the rattle stops, it's just the clutch plates rattling when you pull in the clutch (clutch disengaged), as there is no load on them they are free to move, and there is a gap between the plates, which are vibrating, causeing the rattle.
No problem, normal.

When you are in gear at idle with your foot on the clutch you have placed an axial load on the crank which is pushed forward in the main bearings against a thrust bearing. I suspect a failing thrust face on this bearing as it only works under a clutch release load. The only other point that is under load is the clutch throw out bearing but if that is failing you should be hearing a tinny type of rattle when you have the foot on the clutch

Idle is normally set a bit higher anyway for a cold engine. If the warm idle is OK when the clutch is not engaged and gearbox in neutral, then it points to some kind of severe friction in the area of the clutch throw-out bearing, which may be seizing up, or the clutch pressure plate fingers, one of which may be broken off. If the idle is the same, then that simply needs adjusting.


Is there any odd noise when the clutch is depressed, like a low growl? That will be the bearing. You could have someone listen next to the clutch bell housing while you work the clutch pedal, to try to localise it.

Clutch plates may be worn. You would have to pull the side cover to inspect them. Honda clutch's always rattle at an idle when in neutral. If you just pull in the clutch lever the rattle will go away. Let the lever out and it will rattle again. As for the slippage, if your clutch cable is binding at all it will keep the clutch from fully engaging when you release the handle. This will cause the clutch to slip for a second or two until the cable fully releases from the bind. Any resistance in the cable and you should replace it.