+1

you have to have fuel to have a fireball

 

First thing I thought of was pc3 as well. My boy's Kawi 636 does it too and backfires like a bitch when he lets go of the throttle.

 

this is just how i would explain it from how i understand this stuff, might be totally wrong... but there is always unburnt fuel when you close the throttle, if your running rich there will be more of it but it will cause your exhaust temps to be lower and not burn, if your running lean your exhaust gas temps will be high enough to cause ignition when the unburnt fuel reaches the air outside of the exhaust

 

some bikes have more than others. harley's, for example, have closed-loop systems. most jap bikes are open loop, and the FI system can only compensate so much.



that's a damn good way of putting it. you're about spot on.



see above. backfiring, especially on deceleration, is usually a lean condition. but i understand why people would automatically think otherwise.

 

thanks for the help

but i have another question. do you think putting my velocity stacks in would cause me to run too lean?

 

nope.

but with all the stuff you're doing to increase airflow in and out of the motor, you really should get a PC to match the fuel flow to the air flow.

 

alright, i appreciate it