Topic: Electric start slips

[jensk]

When I press the start button to start the engine the electric startmotor turns at full speed but it seems like the transfer of rotation to the engine slips like if there was a slippery clutch between the startermotor and the engine.

Eventually after about 30 sec's the starter turns the engine and it starts ok. It sound like the starter runs at the same speed all the time. If i remove the points cover i can se the engine turning very slowly and then faster and faster while it sounds like the startermotor runs at full speed all the time.

Kickstarting the engine works ok.

Does anybody have a clue as to what causes this startermotor slip.

Bike is a '76 Cb550F

[TwoTired]

There is a one way roller clutch inside the engine for the stater motor only.

The rollers are in a ramp so that when the inner and outer part turn in one direction the rollers jam between ramp in the outer and shaft on the inner.  In the reverse direction the rollers climb out of the ramp, disengaging the two assemblies.

What you describe sounds like there is some interference with the roller travel (congealed grease?) or roller damage that prevents or delays clutch lockup.

The defective part is inside the lower case.
Remove engine from frame.
Split lower cases.
Remove/clean/inspect/correct the starter clutch.
Reassemble.

cheers,