Vett I dont know of any other here with head work done to there bikes. I would be guessing, just as you are doing. Jetting is alway trial and error. Have you looked at your plug, whats it look like?
Think about what you just said, you can clutch the bike by holding the shifter down. But you have to be coordinated to do it and shut the bike down at the same time. Let us know what you fine out.well i havent run it yet . but i dont use the plug to much because that only show low end condition, because you cant go wide open in 5th and pull a clutch in and cut the motor .but i might need to up the pilot jet too.
NO DONT DO THAT!!! you run the risk of damaging the tranny. Just run it in 5th gear and hit the key or kill switch while still in gear. that will giveyou the most accurate reading as the atv is still under full load when it gets shut off, doing this will not harm anything at all. It will still roll nicely in 5th gear while not running. IIRC I saw people on the HL site running jets in the 140s+ range with a BBK or HC pistons.maybe ill put a wrench on the manual shifter shaft and try that .