need a lil help jetting

hey fellas,havent been on in a bit,been a busy summer with work and plenty of riding!  setting my bike up now for the fall/winter offroad race series here in AZ and I just bought a new FMF Qtech spark arrestor silencer switching from the shorty...im at 4800 feet and will be racing from 3000 to 5000 feet thru out the series...I need some help jetting for the new silencer,i know some of you are running this silencer,i have the gold series SST head pipe and the V-force reed system on stock cylinder any help befor Saturday morn would be hugely appreciated thanks everyone

ohhh crap hahahhaa all of this is on an 01 cr250!!!

It all depends upon how your bikes running. Is there anything wrong with it? I'm not sure just a new silencer would really require a whole jetting change. A severe change in temp/alititude or expansion chamber might though. I would see if you can get away by adjusting your air screw, if not, and your experiencing problems, what range of the throttle isnt responding right and what are they symptoms?

lol haven't started it yet but I know this silencer is more restrictive then the shorty ive been running so im thinking im gonna have to go bigger on the main but im hoping someone chimes in that's got a good starting point for me

I don't think a silencer change is a big deal alone, how ever temp and altitude change matter far more. run it a bit and do a few plug readings-top and mid throttle.

I still have the stock tmx carb on my bike which I guess kinda sucks...I notice changes in the bike with weather changes but nothing so drastic that I rejet...I guess I ll run the bike this weekend and see whats up

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now