Update: bought a timing light last night and checked my timing today by following the YouTube video posted in the wiki. My timing was at 11* btdc. I adjusted it to 16* with the light and it started drizzling so I buttoned it up and took it out.
Acceleration is much better, but I still think there's some additional improvement available. Top speed was 36mph, so same as before. It feels like the pipe hits around 20/25 and then tapers off on the top end. I know it's a low end pipe, so taller gearing is needed for sure. During my 5 mile ride with some good WOT stretches, temps maxed at 330F.
Questions: I have a head gasket on, should I leave it and advanced the timing to 17-18* since I'm still running cool? Or remove the head gasket? Also, it's definitely not 4 stroking at top end with a 75 jet, so I was thinking of throwing an 80 in there. Should I leave the timing at 16 when tuning the carb? Or should I advance timimg first, test, and then tune the carb?
Thanks for the help so far, my timing was definitely off as you all thought! However, I still think there's some room for improvement