hi, i'm looking for stock jetting specs for a 1987 lt500r. I just purchased it off a wannabe mechanic who rebuilt the engine..new bearings, piston etc., but decided to use the old gaskets..needless to say, i smoked the piston due to a leaky base gasket.

I've got the engine back in, but it's got a bog from the mid to the top. He was running a 420 main with the air screw out 1 1/2. I've increased the air screw to 2 turns out and it seems a little better, however it is still bogging slightly. There is nothing done to the machine except for a replacement uni filter. I am in canada, about 800ft asl.

where should i be starting with the jetting. I don't want to do full out runs as the engine is now properly rebuilt and not broken in.