What do you think this *FINAL TUNE* RUMBLE MOD EXHAUST 80cc Snow Motorized Bicycle custom exhaust PK-80 video?
Engine broke in and carb tuned. 1" hole in the exhaust cap
Bike has a nice low sound and high rev!
Stock cdi stock carb higher compression head.
Thing has great low to mid throttle response. Tops out at about 27 because of weight.