[tpryde1]

I'm amazed at all of the individuals trying to push the H.P limits on the poor little 50cc. Pushing H.P beyond design limits will guarantee only one thing.. A greatly shortened engine life. Most 50cc's are designed to run in the 3.5 h.p range. As long time builders will tell you, you most certainly can push more power from these engines. But at what cost? Bearing failures, variator failures, belt failures etc. I have had good luck pushing these units to about 4.5 h.p. beyond this you will ensure an early death to your engine. By design a 9.0 H.p. Kymco Super 8 150cc scooter has larger bearings, variators and belts. I use this analogy because it is telling. By design the manufacturer must determine what integrity must exist to hold that engine together at a given H.P. Sure people are getting rich on all these upgrades. However, you pay the price by a host of failures, that will only compound themselves, unless the entire engine is redesigned. Not practical for most of us, nor sensible. If you want to go 60 mph with a 4 stroke, get a 150cc. Over the last 40 years I have tried countless preformance enhancements. I have found that going beyond a simple 72cc kit, you are doomed to be dissapointed in a short period of time. The second misconception is that you can gear, roller or spring yourself to some unbelievable speed! Taint so! The scooter needs to operate as close to the peak power ban as possible. Get the rollers that will accomplish that at something resembling 7000rpm and you are putting every ounce of H.P/Torque available at the rear wheel of the stock scooter. And if you insist on playing with the engine, well we have already discussed that. Finally a comment about attainable speed as it relates to H.P. The key here is that a doubling of speed results in a 4 fold increase in parasitic drag. Meaning if you do manage 5 H.P out of that 50cc you will not realize more than A 12 or 13 mph bump. Physically not possible. Anyone tells you otherwise they are ignorant or dishonest or both. Smooth scooting!