Help with jetting

[Pokoki]

Hey guys

I just picked of a KFX400 over the weekend. It has the big bore 440 kit, k&n filter (no air box mod), and just a slip on HMF pipe. It is running the stock cam, heads, and sprockets.

The carb was NOT jetted after the big bore installation, and I want to get that done before I really get out and ride.

Any suggestions on where to start with the pilot and main jettings?

Eventually, I will upgrade to a new CDI, 41mm carb, 400ex intake boot, etc, etc, but for now I just want to run and not worry about leaning out on the top end.

Thanks

[locutus]

I have the exact same setup. Looking for the jetting advice also.

[zrydr]

You do not need to rejet for the big bore, re jet for the pipe sure, but there is no difference in the air to fuel ratio needed by adding more CC's if the mixture is correct, then it is no matter what volume your filling.
But with the addition of the pipe you should rejet. I believe there is a jetting recomendation on the HMF web site for their pipe. Still hard to tell due to your specific elevation.

HMF site recomends "for a 2005 and up slip on go to a 145 main at 900ft elevation."