Those rlv karting mufflers work ok, just need extra tacks to keep the baffles in place. Also could cut an angle on the end of the pipe to take the edge off the pop. I like glass packs on 4-strokes but they’re kinda high maintenance, and not really the right look for a vintage build.Thanks everyone for the comments..and yes I could add a small muffler.. but most don’t dampen the sound all that much. At least the few I tried for my limited space.