Hi all. I am trying to fix my brother in law's 1998 Yamaha warrior and i am not sure what to check out 1st. I got it running but it has a miss and the exhaust , right at the head is glowing red because i guess it is loading up with fuel that it isn't being ignited in the cylinder . Could it be a bad CDI or bent exhaust valve ?

 

a lean condition can cause this, could be jetted incorrectly or maybe even really dirty carb causing it to run that way, also a problem with the valves or the timing being off could do it.

 

true about being lean do a plug chk

 

Probably running lean, check the plug. If its white, its lean, and you need to clean the carb or rejet.

 

If it has a bent valve it wouldn't run at all. Also if the headpipe is only glowing a little right at the head during cooler weather, after idling for long periods, or while running the engine hard for extended periods, this could be normal even with proper jetting. If the headpipe is glowing further down the pipe, then it could be a lean condition.