Re: Second Build, vibrating?
If it's sputtering up top it's doing what's called "4-stroking" because it's running too rich. You need to adjust the needle on the slide in the carb. The needle is held in place with an e-clip and there are 3 positions.
Where did you get your engine? I've been trying to find that exact engine, 66/80cc slant-head in black but everyone says they're discontinued, all I can find are silver ones.