I just got my banshee running today!! whoohoo!! I bought it from a friend of mine, and i remember it backfirering like mad at 3/4 to full throttle. When he sold it to me the left cylinder had the piston seized. I took it out, and got the jugs bored over(64.5mm). Right now these are the mods..
Wieseco pistons(first bore over)
PD coolheads(21cc)
RZ350 carbs
active reeds
minor porting and polished
PD proflow 2into1 w/K&N/no lid
DG pipes and silencers
I live in northern NJ, and any help with what jetting set up would be great! I have no experience with the RZ carbs, so it should be fun! Now i just got it started today, so im still breaking it in... i have not gone past half throttle yet, but plan on it tommaro. I am expecting the jetting to be off, so what does anyone think it sounds like i should be running? 300 main?? to big? i have no clue ATM. thanks again.

banshee420, there is a fellow forum member named Kiwi Craig who is all into RZ setups of all kinds with the Banshee's as well as other engine swapping and modifications to all ATV's.

Kiwi Craig's site
This is his web-site. He knows his RZ's.