Just did the PW ring and pinion gears. Big improvement! Now cruises at 35-40 on level ground and I've had the factory speedo needle pointing PAST straight down (6 o'clock) downhill. I'm geussing 50+ mph!
Still only at 50 miles on new 60cc upgrade, so it's still improving. Performance keeps going up.
Thinking about stiffer clutch springs since the point of full clutch engagement is now 15 mph.
Now total list of mods: 60CC upgrade, PW50 gears, air filter housing lots of big holes, 75 main jet, 50 to 1 premix, 2.25 kenda tires front and rear, what's next?
1981 Yamaha QT50: Yamaha 60cc hop up, PW gears.
1994 Kawasaki KLX650
2006 Honda ST1300