banshee sputters and spits flames around 3/4 to full throttle, runs fine every where else

[joey128]

I got a 4 mill banshee, 68mm pistons, 39 mm carbs, 19cc domes I think, v force 4 reeds, scp drag pipes, port job looks home made.  It runs fine everywhere but from 3/4 to full throttle it sputters and blows flames, ive tried richn up main and not much changes and ive tried leaning main and it really wont rev out when i lean it out.  any ideas maybe porting or electrical.

[Bennett131]

Never saw one shoot flames before...maybe lean jetting? Timing issue? Either way, I wouldn't run it like that until I fixed the problem.

[joey128]

ive messed with timing a bit and leaned it out so much were it didn't want to rev out, it acts the same no matter how much I richn it up and acts the same until I get it to lean then just doesn't want to rev out