250-500cc Wr250 Strange idle Rich lean ?

Hi all, its good to be back again. After being in lock down for a year i finally managed to get out on my 1999 wr 250. ok let the story begin, I fitted a new HTM cylinder head along with fitting new boyessen dual stage reeds and a dyno port silencer cleaned out the gas tank and cleaned the keihin pwk carb.

The bike starts and runs fine but has what feels like a off idle stutter like being rich if and then feels like its goes lean and hangs the on idle i did bump the pilot up from 40-42 and the best setting i can get on on the air mixture is one and quarter turns out but still not right.

Any ideas or suggestions appreciated.

Hanging idle sounds lean to me too.. i think youre on the right track there. Have you checked for air leaks (un-metered air)?.. Spraying something flamable (carb cleaner/gas) / propane/map gas has worked for me in the past. Id focus on the intake manifold, base gasket area, and head. Also worth checking the pipe o-ring. Just found a leak on my base gasket tonite and it only had 4hours on it... Good luck.

since you replaced the reeds, you opened the intake, check your seal there