Below are a a few different ways to make your motorized scooter go faster. Some expensive some not expensive and some that i've seen on my travels that are just plain dumb. Below is a list of mods with explanation and rating out of 10.
NOTE: There's only two ways of making your scooter go faster.. increase the RPM of the engine or change the drive ratio. If you change the drive ratio to go faster, you can then modify your engine to regain that acceleration you lost when the drive ratio was changed.
Here is my favourite dumb technique that i found to increase engine power.
Remove the fuel filter, your scooter will go faster because the engine can get more fuel.. what crap. This would only be true if your fuel filter was completely blocked and your engine wasn't getting any fuel. If this was happening you'd know about it!
Having your carb(Carburettor) tuned properly will allow you to get the most out of your motorized scooter. If your scooter isn't tuned properly, it will 'bog' down when you try and accelerate or it may accelerate well but die at 2/3 revs rather than going to full revs. Below is a site I found on tuning carbs with a low throttle state adjustment and full throttle adjustment. Even if your carb has only one mixture adjustment, this site is still useful.. It helped me out.
Changing the standard air cleaner to a high performance K & N filter(that's the only brand I know of for scooter engines) will increase engine performance by allowing the engine to breath easier. Nothing huge but it will. You will also find because its more 'high flow' the engine will probably be a bit louder. This is a great mod however because it doesn't damage the motor.
I've seen some web sites where they say if you drill holes in the air box (where the foam stuff is stored on the carb) you will get extra go. Personally i think this is s&@t..Never run an engine without a filter of some kind. If you drill holes in the plastic air box what's the point of having the foam filter?
Advance the Timing.
When you advance the timing you cause the spark plug to ignite the fuel a little earlier which helps burn the fuel better. Be careful, once you change the timing its hard to get it back to the original setting. I've heard however that advancing the timing on a scooter with an expansion chamber and high performance carb will actually decrease performance. Go figure.
Raising the compression.
1. Remove the washer around the spark plug and then stop any leaks with liquid gasket cement.
I've personally tried this one and I wouldn't do it again.
2. Remove the head gasket from the motor. This will lower the cylinder and reduce the gap between the top of the piston and the spark plug. You can use liquid gasket cement to replace the old cardboard gasket. Have fun with this one! :)
3.The third and the best technique i've seen is to take your motor into a small engine shop and get about 20 thousands of an inch machined off the base of the cylinder. This allows you to keep your normal head gasket rather than removing it and replacing it with liquid head gasket cement which can leak.
Raising the compression of the cylinder using either of these methods could burn a hole in the top of the piston. This is unlikely to happen however caution should be taken.
Changing the gear ratio.
Changing the drive ration will change the acceleration (get up & go) and top speed of your scooter. On scooters such as Go-Ped, Martin Monster and OZ scooters which use a spindle on tyre drive technique, changing the diameter of the spindle will change the drive ratio of the scooter. The larger the diameter of the spindle, the more top end. The smaller the spindle the more low end grunt and acceleration it will have.
With scooters driven by chain and/or reduction gearbox (VIZA VIPER, VENOM, CRUZE also sold under the Tami name) changing the rear sprocket size on the rear wheel will change the drive ratio.
Not very expensive, easy to install and won't shorten the life of your engine. However doesn't 'actually' increase performance.
My opinion: If i had a go-ped or the like, BTW (Monster scooters are in my opinion so much better than go-peds, but that's another article), I would choose a larger spindle, giving say 5-10 km/h (3-6mph) increase in top speed. Then start modifying the scooter by advancing the timing, adding an expansion pipe (tuned for low down grunt), K&N air filter etc. This would hopefully give the scooter more poke low down and mid-range in the rev range. Your finished scooter would have the best of both worlds. More go and more top-end speed.
Expansion chamber pipes
Expansion Chamber Pipes, racing pipes or whatever you want to call them give a marked increase in horsepower. Different pipes are required for each engine to obtain the maximum benefit out of them. Racing pipes can also be tuned to give maximum increase at either low or high revs. Racing pipes will make the engine run hotter so caution should be taken in hot weather.
Using forced air induction will boost performance by forcing more air in, more fuel into the motor giving your scooter more go! If you think you know an idea of going about this, email me cos i want to make one too.