I did a bolt on replacement 110cc to mine...big mistake! The frame is not ready for that power start braking bolts, shaking at 45 to 50 mph. I found wheels need to be balanced. Before i made many mods to the original engine, front sprockets 14 was the best that work with the 50cc , 15 with the 110 a 17 will make it run 55mph . Diferent carburators 16mm,19mm,22 mm. 16 is the best for the 50cc, 19 fully opend for the 110.
But the biggest restriction, beside the CDI, that i found was the muffler, i swap the muffler for a racing one from amazon and everything change. I sold the bike with the 110 and bought a stock one, change the cdi, put a 16mm carb and swap the muffler i am doing 47 constantly