I just put on a new hmf slip on exhaust (on z400) and this weekend I plan on replacing the main jet. The guy at hmf sent me a 165 main jet is this going to work I have read a bit about jetting and I get a mixed signal about the difficulty. The guy said that all I would have to do is put on the exhaust and replace the main jet with the 165 sound o.k. to you guys? I will also put in a new k&n air filter today need help please?

 

All I did to my Vinson was put the pipe on, put a 145 jet in,adjust the air screw, and put a k&n air filter in. Check this out.http://www.hmfengineering.com/suzz4.html

 

What is the noise factor of the HMF muffler compared to your stocker?

 

I can tell a huge difference in sound but have not ran it yet to see the power increase much more throaty

 

i have hmf slip on z400 i tried a 165 dino jet in mine it would not runn with air box lid on but it runn damn good with out it might tri a 170 mj jet to see if runns any better.