I have adjusted my valves put new plugs in Im runninglike a 167 main jet I put the needle jet to make it richer but according to the plugs and how the engine sounds Im still running lean. The problem is it sounds like I still have a popping noise coming out the stock exhaust now at wfo not loud but you can here it. I checked over all the exhaust and intake for leaks cant find any air leaks not sure why im still hearing the pop noise and why its still a little lean. Yesterday Im was getting about 4200rpms just me in the 1652 so the motor runs and idles ok just not sure what else to try and adjust. Thanks for any info

Try to preasure up the cylinders with the rockers off and check for valves leaking. Im not talking about compression test im talkin leakdown. Its kind of hard to troublshoot this with out hearing or seeing the engine in person. Ive seen heads crack between the valves and that could be the cause of this.

Didn't JD run lean from his rubber Mikuni adapter or primer bulb.....or something like that?

How did you check around your intake for leaks? I would spray some brake cleaner around the intake and carb while its running and see if it changes your RPM's. If it does you have a leak.

wouldn't hurt to pull da nut off da flywheel and look at ur timing key to make sure it ain't sheered.... it's happened before.