Re: Loss of Top Speed
Check valve gaps
Check spark plug condition - you want a nice light tan brown colour - anything else and you have a problem. Pale/white running lean (very bad) black and oily - oil blow by (not good) black and sorta sooty (engine too rich)
Check exhaust - while running it should be impossible to see anything unless the weather is very cold - black smoke at high/full power (too rich), blue smoke at anything over tickover (oil blow-by and combustion... bad.)
Check fuel supply for crud and or disassemble carb (DONT if you dont know how to or havent done it before, bits will go ping)
Brakes for binding - that will noticably affect top speed although it sounds engine related tbh
Check fixings and fittings
Do you have a speedometer fitted - if so do tests to see if you're down on speed or its just the engine bedding in makes you think so
Have you changed fuel suppliers or gotten it from a different garage - that can have an effect.
Check all intakes/outtakes are clear and operating normally - increase in back pressure.. not great and will stifle the engine...
"....Look, no pedals... *thud*..." The mating call of the motorized-biker.
"RetroEagle" - 32cc Two-Stroke, Piped. 35mph on #13 gear. Reversed stem with springer fork.