Hi, I got my 86 k100 with 85 motor installed and running well , thanks to your help. I started it yesterday and ran it for awhile to get it hot and change the oil. I was not able to change it and went to start the bike today, and start over, and sprag clutch wont catch. I took out the starter, and with my finger can spin it at will. I will push start the bike and run some detergent thru it , my question is can they acually break or is it just dirty?
Thanks for all the help.
Brian

Hi Brian,
I would drain the oil as it stands now not push start and heat it up. I would then change the filter and refill with some high detergent oil like Mobil Delvac or Mobil 1. These gently and slowly remove sludge and put it into suspension to be removed by the filter.
You may not be thinking of adding a can of flushing additive but if you were I would advise that you don't. This is because if the engine has got a build-up of sludge from poor oil or infrequent change routines by previous owners the flushing additive can break that sludge free with the result that critical oil pathways can get blocked and serious engine damage can result. I recall an engine builder friend of mine saying that in his experience the flushing additives often cause engine failures and to resuscitate an old engine use a good diesel oil with a high detergency to clean the engine slowly.
Regards,
K-BIKE

Brian,

To answer your question, I have not seen any broken sprag clutch but saw few of them dirty (gummed up).
Most of the time one or two flushing of the engine will solve the problem.
As K-Bike stated, it may require some time for the clutch to be cleaned.
Be ready to push the bike for a couple of days.

Hi , the good news is that babys so tuned up, I can jump start it in my 24' shop . I'll let you know when the clutch is free .
Thanks ,
Brian

Hi Brian,
Last point is that as our bikes do not put the clutch into the oil so it has the opportunity to shed abrasive particles into the oil like most other bikes there there is no need to worry about any oil you use being too slippery so the more slippery the oil is the better. There is no issue of needing to use motorcycle specific oil with our classic K's I am pleased to say.
Regards,
K-BIKE