"got it out again today with a leaner mix of synth and it ran pretty peppy—!
still rich but strong not doggy…."
If the kit has only several hours on it wouldn't it be smarter to use mineral oil to break it in?
"I’ve got a stripped out exhaust stud and my leo pipe is only one with one bolt, so i’ve been running it with the mixture screw all the way in, which I assume is extra-rich, to make up for the lack of seal in the combustion chamber. It sucks. I tried heli-coiling today but messed that up. I’m going to have to try it again with a bigger tap."
You have that amal carb right? The mixture screw is only for the when the slider is all the way down! (idle) Am I wrong? You'd need a bigger jet. This won't save you while runnign full throttle. Be careful ben, if there is any plastic anywhere near that exhuast port it could start melting