Join Date: Jul 2008
Location: Railton, Tasmania, Australia
Re: Starter free spins on occasion
If you are certain that the starter motor is actually spinning (powered up) then it is likely that the starter sprag (overrun clutch) is beginning to gum up and slip rather than grip the hub to turn the engine over. Plenty has been written about the issue here. Search starter sprag clutch. In the K100 days I always used a high detergent diesel engine oil and never did short runs, this ensured the engine oil always came up to operating temperature so reducing the chance of forming condensate and sludge, both enemies of the starter sprag.
1987 Yamaha TY250R
1991 Aprilia Climber 280
1988 K100RT (the pack horse)
2005 K1200LTE Light yellow metallic