hey not to make this more complicated or open a can a worms on this subject,but the info you guys are putting out on this machine kind of contridict what dyno-jet says.According to their spec sheet that comes with the jet kit (stage 1)at sea level they are saying with a after market exhaust and filter(twin-air),that the main jet should be 124 main(for qwiet exhaust)Example HMF Eco or FMF Powerline.With hidg flow baffle they are sayingmain jet 126.So i was just wondering why you say 142 main?I would just like to know so when i do this i get it right the 1st time.I guess i will have to order #38 pilot also?And what do you guys think about the 2 exhausts i mentioned.Which one?I would like to keep it as quiet as possible.And what's this about drilling the air passage?It sounds like a good idea but i'm a little nervous about drilling my carb and making a mistake.Fill me in a little bit more,and tell me it ain't no big deal.Ok thanks all for any input that you can provide.God save the Republic!

 

The 142 is a stock Keihin jet number that HMF sends with their pipe. The #38 is also a Keihin number. The Vinson's have a Keihin / cvk-36 carb on them with a #128 main and a #35 pilot. The 142 Keihin is equivilent to a Dynojet brand 128. These are just good starting points for jetting. Every bike is different, but who knows you may get it real close with what has been recommended. I have two 05 manual shift Vinson's and have the HMF utility exhaust. I really like them, but I have no experience with the FMF. Hope that clears things up for you a bit. Good luck..........