Hi. I have a 2001 Yamaha Banshee and I'm having trouble with jetting. I've just installed some 65mm pistons, cpi in frame pipes and no filter box. I'm currently using main jet size 260 but it has no power. Timing advance is set to +4. Needle clip in the middle and stock needle jet. Any advice?

 

What is your compression?
I'm running 320 mains in my 4 mill at sea level. Try 290's or 300's

 

I didn't measure the compression yet. I'm gona try it with a bigger one.

Tnx

 

with a mill head on mine with t-4's and .030 milled head i was sitting at 150psi compression and ran a 300 main

 

Sounds like you are rich what altitude you ride at?. Im set up close to you at 5800ft and running 240 with no box