250-500cc fmf gnarly and turbine core 2

hi guys,ive just fitted a fmf gnarly and turbine core 2 to my 09 wr 300 and was wondering if anyone has the same pipe set up and could gimme the jetting specs they are running ?

i searched through the jetting database and couldnt find anything,i live in the uk where at the mo the temp is between -1c-5c and 110m above sea level,with the new pipe between 0-1/4 throttle i cant hold a constant speed/throttle its very hesitant ive got to be constantly rolling the throttle on to accelerate,past 1/4 throttle it flys.it feels as tho it is running rich as im getting quite a bit of smoke and it burbbles.

it has a 40 main and the needle clip is at the top,air screw 2 turns everything else stock,when i bought the bike it had the stock pipe and a 40 main in it so im thinking 37.5 pilot or 35 ????

any help much appreciated guys as im dying to get this out on the trails

sorry temp is -1c to 5c

You will probably need to go down a bit on the main jet as well.

Put a 37.5 pilot in, put clip back to the 3rd groove ( middle ) and 2 and a half turns on the air screw and it's running sweet !!

now put a 14 tooth front sprocket on it and it spreads the power and makes it super sweat !