Just had an HMF Exhaust installed on my 650 and know I want to do some modifications on the air box / air flow. HMF offers a high volume K&N air filter and a jetting kit but I’m interested in what other riders have done on there 650’s. Has anyone modified their air box or add a snorkel? I thought about drilling some 11mm holes on the top of the air box cover, but we ride lots of creeks and rivers and I’m concern about water getting in. Any suggestions?

I haven’t had a chance to ride it other than in a field next to my dealer’s shop. The exhaust seemed to increase the power band across the board and when I shut it down at 57 MPH it didn’t show any sign of letting up. In our garage my son punched it while it was in 4-wd and he spun all four wheels! So I can’t wait to ride it tomorrow. Anyway I am open to suggestion on how to best increase the airflow and still be able to tackle deep water.

 

hey Oldman does HMF have a web site or phone# Ive been looking for that airfilter jet kit for a while. If you do any water crossing at all I would not put any holes in the air box.

 

i would like to know where you got the exaust from could you give me an email it would be apreciated and if you know of any other perfomance parts could you let me know

 

hmfengineering 216-631-6981 have there slip on on my grizzly 660. they are awesome.

 

Pro Circuit has a very good system with stainless head pipes but it is a bit pricy. A spark arrestor comes standard and a quiet insert is an option
Bearman

 

what main jet would flow more
dynojet 160 or 170 mikuni
i know it's tought call just thought somebody might know.

 

I ordered my HMF pipe, silencer insert, jet kit and Twin Air filter from Mike Penland. Mike is one of Kawasaki's factory riders in the GNCC series and rides a 650 - so I figure if it's good enough for him it's good enough for me. His phone number is 706-746-2812. Just tell him Bob from Iowa sent ya.