moped type: 50cc, 4 stroke, 20009
Not much with an engine that small. Make sure your tires are aired properly and the engine is tuned, particularly the spark plug being clean and correctly gaped. Ditto with the air filter.
Drive down hill...or with the wind at your back so it will push you..i guess you could bore out the cylinder (there probably is only one), or just drop in a new engine, but probably not worth it. i would honestly say if you are looking to go faster or have more power or looking for new thrills, maybe look around and up grade to and engine with more cc. especially if you buy something that is slightly older (i like to call them vintage...not old, haha) you could probably save some money and upgrade to 70cc, 90cc, 125cc...it all depends on what you find, just be careful, you might need a motorcycle permit/license.
not much other then modifying the motor... better to upgrade to a 100cc
Depending on state laws in the US the 'moped' is legally restricted from going faster than 20mph, 25mph, 30mph(most states) or 35mph. depending on manufacturer the restriction can be done with ignition control governor or carburator restriction- some 4 strokes may have transmission variator shims in belt drive pulleys. First check shop manual for restrictor method used on whatever manufactured moped you have- do you have pedals and direct drive engine to wheel? Check manufacturer and see if there is a model that looks like yours but is not speed restricted- does about 40mph or so for some markets- reset your project to that models pattern. Basic hot rodding techniques would apply- open exhaust pipes, larger carburator for better air flow, lap/machine head or base of cylinder for increased compression, maybe get sneaky about increase bore size if you don't mind risking legal hassle for having a 'motorcycle' in stead of 'moped'. Vague rumor that Honda Ruckus 50cc can have a 72cc cylinder put on case. Old Puch 50ccs often had 70cc cylinders put on them- they were 2 strokes though. ** further fun info- saw a moped plated Yamaha at undisclosed shop today- has a 70cc cylinder on the 50cc numbered case, state records have that part number as moped so don't check further when issueing moped plate, shop mech said it will reach 65 with large rider(him) on it, owner keeps up with 45mph traffic easily. Mech said could convert old CA50 drive to 35-40 mph shim when I want new drive belt.**
