YZ 250, no spark

[soccer2963]

Hey guys, im new to this forum, so any help would be great! What i have is a 1987 YZ250. It will run great one minute, then will not start for a while, or a whole day. Now when it is in this NON starting phase, i checked everything, and it is not getting spark at the Spark plug. Now, how do i check the ignition system to see which part is bad? How do i check the CDI, The coil, The stator? The kill switch is good, i checked that, that is not the problem.

Also what years of parts will fit on my bike? Because there is not too many used items from a 1987 YZ250 for sale on ebay. But there is a 1990 YZ125 coil for sale, and it looks about the same? Also i would like a spare engine, or cylinder stator you know. What stuff would fit?

I do have a 1985 YZ80 also and would like to have some spare parts, what woud fit this bike? Thanks.

[Racerafm50]

It may sound crazy but my dad tought me this one years ago.... Pull the tank off of the bike wait till it's dark out and turn all the lights off in the garage so it's pitch black then have a freind kick it over ( not the bike, the kickstarter) while you move the wires around looking for any kind of short. If you have a short somewhere you'll see an ark sorta like you see at the end of a spark plug.

It dosn't always work but I've had it work for me a few times over the years.

Good luck!