Brother-in-law put on a 38mm carb and needs a richer needle. He got the smallest one from the dealer but it's still not enough. Does anyone know a company that has a listing of needles and other carb parts for the pj38 keihin.

Try CARBPARTS,com
they have charts to find richer needles, just find the number one the one he has.

Solve all your carb problems, buy a Keihin PWK 35, or 38 air stryker like I did, $160.00, the best money you will ever spend. I tried everything with my Mikuni, main, pilot, needle and seat, needle height,float hieght, everything I did would change the characteristics a little, but I always had some kind of a problem, pore idle, sputtering, fouling plugs. I have not touched my Keihin, or even changed a plug since I put it on a year ago.