2003 XR-400R Why is it overheating and missing?

[snb73]

I installed the rings and that cured the smoking problem. After buttoning everything up, it started on the second kick. I noticed the headers were glowing read and the bike had an intermittent stumble. It happens about every 20 seconds at idle. It's sounds like a miss fire with a "psssttt" sound like a back fire.

I think I may have advanced or retarded the cam one tooth. I set the timing by placing the "T" on the crank in the view hole and the cam hash marks at 9:00, 12:00 and 3:00 respectively.

Any ideas? Thanks, Steve.

 

[Rich Rohrich]

If you advanced the cam timing a tooth it would open the exhaust early and really dump a lot of heat in the pipe along with making it run pretty bad. Check for air leaks near the carb first. Cracking of the intake rubber is common. If you can't find anything pop the valve cover and double check the cam timing.

 

[snb73]

Thanks Rich.