I just recently purchased a Banshee power kit that included FMF pipes, silencers, reeds, reed spacer, and boost bottle along with an assortment of jet sizes. I am planning on running Sonoco 110 racing fuel also. Most of my riding will take place at Waynoka, OK. Could somebody please give me a good idea where to start with the jetting. I still have the stock airbox also. Thanks.

 

Might want to start off at 300 main jet, might be too rich, but I think thats a good starting point, also you MIGHT need to up the pilot to a 30 or 35, just check how your throttle response is and the color of your plug.

Oh yea im assuming the riding spot is close to sea level.

99 Banshee

 

With those mods...there is no need to run race fuel...Not until you start increasing the compression of the engine...(look at the pic in my signature...about the same mods as you)
I would say to go up a couple of sizes on the main jet.(stock ~240?) Around a 260-280 should be fine for starts. Do yourself a favor and get a prodesign filter kit. It will help your engine breath better.
There are many arguments on where to put the needle clip...I would leave it stock for now. You will know after a little runtime which way to go.
I wrote all the specs down...But do not have them with me at work. If you need more specific info...let me know.

 

1)If you are running with the stock airbox lid with no holes try 260 mains.
2)If you have an aftermarket filter and are running without the lid try 30 pilots and 280-300 mains.

 

I have a 98 banshee with stock bore. FMF pipes & silencers boost bottle and Pro-Design intake. I called FMF to get their recommendation for this setup and they said 30 pilot jet with a 280 main. Stock needle in center position. I run a 290 to be on the safe side because I have no airbox and it runs fine. The pro-design intake is a necessity if you don’t want to suck dirt into your precious motor. When rejetting always start richer than you need and work your way down depending on plug reading. 92 octane is fine if you have stock compression. Just my $00.02

 

Thanks alot for the feedback. I am hoping to get this done this weekend so I can get back to riding.

 

My original post had an error in It regarding the jet sizes. I stated 380 and 390 when it should have said 280 and 290. IT IS NOW CORRECT. Sorry for the misinformation.

 

I pay more attention to my needle jet settings than anything else. That controls most of the throttle range. Only you can figure out what main jet you need by trial and error. Where you ride and weather conditions have a large impact on engine performance.