I know this is beating a dead horse, but I have a 98 500 scrambler that is backfiring very LOUD through the exhaust, and shooting a 2 foot flame through the carb when attempting to start. I have scoured the forums on this and below is a list of what I have checked, done.
Compression is 110 psi.
keyway is NOT sheared
cam timing is correct
good strong spark
lots of fuel, too much fuel almost
I have pulled the flywheel 2 times to double check the keyway
Exhaust valves are traveling full stroke and the lobe is perfect
I don’t know what I am missing. This seems like EVERY other 500 problem I have found on line yet everything I find here I have checked. Any idea what I am missing??
Thanks for the help guys