Sputtering/Backfiring Trouble

[Wingnut]

Over the last three weeks my YFZ has started having trouble. It started as just a little sputter, but lately it has gotten to the point where it won't move under its own power. For about the first 15 minutes of a race it will run great then it will start to have a little hesitation and after a few more minutes it will start to backfire and after about thirty minutes it won't even rev above idle. If I stop for about 5-10 minutes it will run fine for a short while and then it goes back to hardly running. I've checked all the basic stuff I can think of, but if anyone has any suggestions please post them.

[BigAl]

It sounds like a heat issue with your CDI or coil?

I am sure you have changed the fuel, and or checked for water or dirt in the carb.



I',m not much help I know, but If your fuel is fresh and CLEAN, I would try to get your electronic components checked out.

[Wingnut]

That's what I was thinking, but I can't take it anywhere until Tuesday. I have dumped out the old gas and put some fresh in and taken the carb apart and cleaned it, but the problem has continued to get worse.

[Maxx_Action]

Yup...

sounds like a bad component in the CDI. Fine when it's cold, but under operation as it heats up integrity breaks down and it basically shorts out. Good luck...

Maxx