no matter what jetting setup i have doen, i cannot get it to stop popping out of the silencer. sometimes it is a loud back fire, or sometimes it is a quiet little pop. could it be my exaust is not on all the way? i ran it rich, i ran it lean and it still makes the same noise. IT is a GRaydon full exaust, could the popping be from simply being a Straight flow exaust?? can someone please help me.

 

Usually, 9 times outa 10, popping after letting off the throttle is due to a mal-adjusted idle mixture screw, which has to be adjusted anytime jetting and airflow is changed.
Turn idle mixture screw inward until motor starts to bog, then start turning outward - while counting every half turn - until the motor starts to bog again. Set the screw exactly halfway between the two points of bogging and the popping should be gone. Any time you change the main jet or needle position, or change your intake or exaust flow, this needs reset.

 

i did that also. can this popping and back firing be from the float level? i read that soemwhere and it said i might need to adjust the float level, would that be true??

 

Any air leaks on the intake side ?

 

buttfungus, do u mean where the pipe connects to motor?? sorry i'm mechanically challenged.

 

I think he means between your carburator and heads, I.E. intake manifold o-rings or carb boot loose. Thise could cause a lean condition very easily.

 

Yeah, DemonDS, that's what I meant to say thanks!