I got mine running today. I could not leave it alone so I took the cylinder off and cleaned it up. Years ago I added a boost port, I did it with a large die grinder, looked poor, so I cleaned it up and enlarged it. I lowered the intake port and cut the skirt on the piston. Years ago I notched the top of the piston to raise the ports, you can see the mods in the pic's. I did the mod on the carb, they say you can drill them out, but if you do it will not close proper so I made the venturi oblong so as not to cut the thin sides. I moved the timing ahead slightly and increased the size of the exhaust hole to about 1/4" I also found the two small holes that feed the carb too small and increased them out to 1/4 also. I don't want to race this thing but I would like it to get up and go if need be. Ill put up a few pics of the barrel. I like the way it sounds now, it no longer just takes its time revving up, it actually sounds like a small motorcycle. Have fun, Dave