Jetting !!!Help!!!

[tsargent4]

I have a 2003 400ex with a fresh build on it that includes: JE 10.8:1 (416cc) piston kit, Hotcam stg 2 race cam, Uni air filter w/ lid on, FMF Powerbomb header and Powercore 4 slip on. I live in southern (Bedford) Indiana and as of right now I am running my carb with a 165 Main, 40 pilot, and needle on 3rd slot. I have done trial and error continuously and can still not getting my jetting right. I have tried running a spark plug that is a step hotter and I do run 50/50 fuel (110 race fuel and 94 octane). Once the motor gets good and hot and I let it sit and idle for about 15 seconds it wants to idle down and die(It's not in the idle screw though, I am thinking I need a bigger pilot jet). Also when climbing a fairly big hill in 2nd gear it wants to lose momentum to the point I have to go wide open throttle to get up the hill, but it still struggles. My question is this, what jetting should I have? or try? do I need to get a DynoJet kit or FMF Power up kit? It is to the point I can't ride because I don't want to blow a fresh build just because the wrong jets were used. Any suggestions or help would be appreciated. I am looking for an answer from someone who KNOWS what they're talking about, not stupid answers. Thanks.

[RaginRedneck]

This may be a stupid answer, but take it or leave it.

Have you done a plug check on it?

From everything that I've read on here about jetting and talking to my buddies, checking the plug is the best way to help figure out your jetting. Start there. From what I saw in your signature and your post, your jetting sounds close. I would go to a 42 Pilot though, they are inexpensive anyways.

[tsargent4]

That is my next step. I plan on getting a 42 pilot and will let everyone know how it works in a few days. Anymore help would be appreciated. Thanks.

[tsargent4]

I forgot to mention, I did do a plug check...and the plug electrode was light tan to brown color...it was normal...it had a few white pencil head size white spots on the tip of the thread part buts thats it...

[Hondamaster5505]

You shouldnt be running race fuel. You only need it if you run higher compression that 11.1:1

[tsargent4]

It won't affect it...It's 50/50...I am not running it straight race fuel...I have a 5 gal tank...2.5 of 94 and 2.5 of 110...not going to hurt it...