small ignition problem

[pinky44]

Hi I have a 1986 GSX 550 which seems to have a cdi fault engine starts and runs for five to ten mins then quits and wont restart for at least 20 mins I have got a replacement cdi and it still does the same thing. And then no spark at all then it can sometimes get a good spark at the plugs when out of the head but wont fire.(The maual says that ON rare occasions a plug that appears to spark vigorously will fail to do so refitted to the engine and subjected to compression pressure) never heard of that before am stumped on the remedy for that. Dont know if it is a linked problem in the ignition circuit????? There are no fuel problems it just wont fire up.
Any help out there as driving me nuts.

[t3rmin]

Had a very similar problem myself. Replaced igniter/pickups with Dyna S system and installed new plug caps. Fixed it right up. Check that your coils are getting good voltage and have proper resistance readings as well. Lots of info on these things in the archives.

And be sure to try a fresh set of plugs!

[GS850_Coug]

That really sounds like more like a coil issue to me. Many times when the coils are beginning to fail, they work okay when cold, but produce a weak spark when hot. It can also happen they don't get enough battery voltage to them. The other possibility is the signal generator may not be putting out a good signal. Not likely to be the actual cdi since you tried a second one with identical results.

[pinky44]

Many Thanks

Thanks guys the fault was driving me crazy. Thanks to your posts i was able to trace the problem to the signal generator one side had failed.

so thanks for the help.