I've posted this topic on the Zuk forum before and haven't found many people that know about the Keihin Carbs. I was hoping I would find some help from the honda guys.

I have a Keihin PJ 36 for my 87LT250R. I put it on and it started and ran great, but would not idle. When I adjusted the idle screw it did nothing. Could this be caused be an improper needle height, or a pilot or main jet that is not the proper size. It does seem to be much smoother carb then my Michuni, but I need it to idle. As soon as I let off the gas it dies. The carb has been disassembled and cleaned with carb cleaner. The jets all seem clear. I have a 150 main and a 60 pilot. I have heard there could be a problem with throttle valve. I took it out to look at, but don't really see what could be wrong with it. Is there anything I should look for on the throttle valve. I sprayed the carb and boots with starter fluid while running to check for air leaks and it seemed fine. Any ideas would be great. Help.....

 

I think your pilot is to large, try a 45 or 48, I'm running a 48 in my 38A/S, it came with a 50 and it idled poorly (very slow) with the 48 it's fine.