I recently cleaned and rejetted my cv40 with a performance kit from CV Performance. I drilled the slide with the bit that came with the jet kit (7/something, not 1/8 or larger), replaced the accelerator pump diaphragm, and the previous owner had replaced the acc pump nozzle with one from a Thunderslide kit (whoever had it did a piece-meal, crappy attempt at stage 1 upgrade, hence the issues I was having). I jetted it using the 44/175 jets. The it also came with 45/180 jets. I have SE Stage 1 high flow breather (the old ham-can style) and SE 2 high flow pipes. If I pulled the carb and rejetted to 45/180, would I see a pretty good power increase? Bike runs great right now, but I don't feel I am taking full advantage of the SE breather and exhaust. Thoughts? Go larger, or stay at one step above stock?

 

45/180 jets are perfect. With any open air system the bike will breathe better. Increasing the main jet will not make any seat of the pants difference. When you change the cams and get the heads ported, then re-jet the main. Till then ... enjoy.

 

use the 45 180 with stage 1 and pipes , look at the pipes near the head if one is discolored more than the other the bike is running lean and raises the cylinder temp too high better rich than lean. I have stage 1 ported heads and straight pipe and run 180 45 but i need 185 45

 

What needle are you using?