Re: strange bogging at 1/2-wot
Have you tried it without an air cleaner? I always drill a few extra holes in mine- if it runs the same without it, then something else is the problem.
I played around with the petcock when I built my first and closing it down had an effect- proving it was getting to much gas to air somehow
I also got better results back then adding a little more oil to the mixture- not sure why, but I tend to regulate mine now by smell and how much oil and smoke seem to be coming out- I've found that oil eventually tends to accumulate in the system a bit and have used less since break in.
Get a straight billet intake if your motors fairly level- its the greatest performance enhancer of anything else and less than $20- I like the regular without the "boost bottle" fitting. Anyway it gets the carb closer to the motor and that really helps the flow.