backfiring 650 xj 80 mod

hi all

well yet again the beast has caused me stress .it back fires 7 inch blue flame out of right side exhaust

any info would be great

thanks john

 

Backfiring is commonly a fuel mixture problem. To find out for sure do a search of the forum for backfire. There is lots of useful info there.

Good luck!
Rob

 

Basic rule of thumb is backfire through carb is a lean condition and backfire through exhaust is rich. Can also be a timing problem.

 

well blue maxim

im all ears dont stop there how can i fix my bike ahhhhhhhhhh its drivin me crazy

 

Colortune the idle mixture then sync the carbs. If you don't have a colortune you will have to do it Rick's old school way. Check his post for that. But in short, pull the #3 & 4 plugs and check which one is sooty. Turn the mixture screw in on this cylinder's carb about a half turn at a time until the backfire stops. If none of this works then check the valve clearances, followed by the timing via the timing marks and timing chain slack.