Motor broken in! Time to Modify!

when you put on an expansion chamber you have to lean the needle and enrichen the main.
for "bottom end" you need to lengthen the header, not shorten it.

I'll get a slightly larger jet for top end...The header was way to long to get any response from it to begin with, I think. It gets on the pipe now at half throttle, 20 mph which is where I want it. Thanks.

Problem solved! It felt like it was running outta fuel on high rpms. I lifted my float spring so it was always full. Done! Doesn't bog, 4 stroke, exhaust turns on at perfect rpm, It screams! Gets up to speed quick and tackles hills faster with the smaller gear! Stoked on this 66cc. Thanks for the tips. I'm figuring this out. Now to work on my girls bike I got for $60. Phat beach cruiser, motor works, but has no compression. Can't get high rpms. It was all in pieces.....

33.4 mph on flats, no tuck, 175lbs
41 tooth sprocket
blueprinted motor
SBP exhaust w/ extended header