Jetting 38 a/s

[blb515]

Could someone give me a good starting point for jetting a 38mm a/s for my 250r?

My mods are:

paul turner type 6 pipe
k&n filter no lid
ported cylinder

right now I am running the stock carb with a 158 main.

any help would be appreciated, i am pretty inexperienced with jetting...

[8dave3]

I have a Sparks pipe,portedfor mx,no lid with the A/S.I run with a 165 main but dont remember the pilot size.