higher compression (need help)

I have a wr 400 '00 that is big bored to a 426.It has 13.5:1 aries forged piston,bk,hb mod,yz timing,stock uncorked pipe and carb stop cut.I am tring to figure out the carb tuning.The carb has a #170mj,#42pj,obdrs needle clip in #3 position. I also run 105 unleaded fuel for the compression. It runs great and starts on 1st kick every time but it still stumbles if I hit the throtle hard from idle. My altitude is 900'. Can anyone help me on the fine tuning with higher compression on this bike. Maby one of you guys have done this to your bike.

the compression has very little to do with the carburation of your bike. it's more critical to get it right but that doesn't mean that it has changed.

thus your comment that it still bogs (nothing changed then heh!).

your needle is **** . get a DRM a DTM (thus were all pulled out of the 98 and 99 bikes for E needles so they're going to be sitting around) or DMM (especially if you ride up in the clouds somewhere.

you know that the E series needles give more midrange. EKN, EMN or EMM will all do. and others but get a needle that finishes with M or N.


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