426 kit/stage2 cam jetting help

[ATC350X 85]

Im helping my friend do a J&E 426 kit with a stage 2 hot cam in an 05 400ex, hes running a yoshimura exhaust no lid with a uni filter, before the cam and 426 kit he was running a dynojet 165 main and the clip lowered one position from stock, i believe the fuel screw was around 3 turns. I dont think this setup is gonna be ok with the new piston and cam.

I want to get the jetting close to what it needs to be before we finish the job so the bike is ready to go upon break in. Does anybody have a baseline as to what the jetting should be around with that setup? If we have to put oem jets in it we will. Thanks

[prepracing]

that 165 should still be close to being right on, as long as the same pipe and filter set up are being used and no head work was done then just the 426 bore and cam should make no big difference in jetting

[ATC350X 85]

Ok cool, i think he was running a little rich any way, good to know we get the cylinder back in a week,:devil: If its too lean then we'll throw the lid on and go from there.

[GOTFEAR]

I"d try 150 or 155 main 3rd cl. on 110 race gas with the air box lid removed 165 might be two mutch 3rd cli. is good