I built this bike over the winter for the Zeros 50/50 competition, the only rule was that we had to use e50's, the rest was up to the builder. I did the normal e50 rebuild, but for the cylinder I'm running a Tomo 50cc Airsal, I feel lie these kits are way under used, they have better porting then the 64cc counterpart, paired with Athena reeds (my favorite 2-petal reeds), MLM Rev-Run cit to fit the crazy exhaust port angle, stock points, and a 2-shoe clutch with blue springs. I have been very pleasantly surprised by this bike so far, its real quick off the line, with 17x45, I only need 10k to hit 50, wish me luck. When the weather warms up I'll have some real numbers for this thing. EDIT 50mph ACHIEVED