250-500cc More Carb Questions

Hi All, I have acquired a 38mm Air striker for my 09 WR250 it came with a JD jet kit. Its running Blue needle 2nd clip from top. 175 main 45 pilot air-screw 3 turns out.
I am having a night mare trying to set this up. First thing is there a definitive way to set the float height . Have tryed the 60 Deg 16mm to top of float then told that no good as it still compresses the valve ? .

Were i ride is approx 0/600m above sea level bike has only 2Hrs on new piston rings and reed petals, Cleaned out and checked P/V when i did piston.

Any a all help gratefully received.

Many Thanks Dave

check u tube for videos on carb height check

Id start with needle in the middle - air screw at 1.5 out

check pilot ( may be rich )
then check mid - needle
and then main

FWIW my 125 had a lean bog with blue needles on 2

Rockdancer- quick question [small hijack beg pardon] what needle did you prefer? I am messing with a 2006wr 125 and getting closer tmx carb'1200 ft/60 degrees- still a little lean off the slide onto the needle Ever try another slide?

Thanks for the input, will check out u tube.

I used standard needle 60 ? and slide on old tmx. Worked fine for me. Only seen guys going for bigger slide
Sure it's lean ? Hard to tell as rich can feel like a bog