Jetting question

[450rcrazy022692]

I cant seem to figure out my jetting so i was wondering what other 450s were running for thier main jets.....I have a 170 in there now with a Yosh full system, 13:1 piston, hot cams, and thats about it

It backfires on the decel so i take it as running rich.....do any of you guys run lower than 170?

[GPracer2500]

For an 04, a K170 sounds lean not rich. (I'm assuming you're running a modified or removed airbox lid?) The main that comes with the HRC kit is a K185 for an 04/05. Not that a K185 is always going to be correct but it should get you in the ball park. When comparing jetting used by others be sure your comparing with 04/05s. The 06+ TRX450Rs use a different carb and the jetting is totally different.

A backfire on decel can be caused either by being lean or rich--but when it happens from being rich you generally have to be WAY rich. And it sounds different too. Your main jet probably doesn't have anything to do with it though. It's far more common to get a backfire on decel from being lean on the pilot circuit.