If the bike has not been run for a while, say a day the bike will start normally, run but then stop after about 20-30 minutes. The bike will normally then not start and if it does it wont run for more than 3-5 minutes. I think the problem is related to the electrical system and heat but im not sure what the heat may be affecting. The coils look OK. Where should i start looking?

Luke, May 2008

Another thing that might be worth looking at is the fuel cock, I had similar problems but everything happened a lot quicker in my situation i.e. the bike would stop after 3-5 minutes and then only go for 30 seconds. Therefore I don't know if my suggestion will help seeing as the time periods were so different. But the problem with mine was a) a rusty fuel tank and b) a clogged fuel cock because of the debris, so after thoroughly washing all the components of the fuel cock and cleaning out the fuel tank the problem was solved. I hope this helps/has something to do with your problem.

Michael, May 2008

k100 have 2 coils,try the plug on the head trick from previous answer ,if no spark on anyplug suspect ignition trigger assembly its on the front of the crank

caine, May 2008

Coils can look immaculate and still be breaking down, the problem that you have described sounds like a coil,when problem occurs next time, take off a suppressor cap and remove a plug and see if you are getting a spark.

debbs, May 2008