Try T-Bolt.com................
The absolute way to get brute force power from these engines from 50cc-110cc is to overbore the stock cylinder to 55/56mm's then regrinding the stock camshaft and adding a performance CDI,HP coil w/HP sparkwire,25mm carb from a Honda ATC185 with 25mm TRX90cc intake and modify the stock exhaust plus some portwork.....
Theres other parts I use too that were available in Japan amongst the super serious monkeybike tuner crowd who developed roller rockers for these engines 8 years before even being available in the USA and made by Takagawa....
For me doing the mod was very cost effective and cheap seeings it costed me nothing to have the cylinders bored and I reground the camshaft myself.
Hardest part is finding a proper headgasket..
Good Luck
Stock 110cc cylinder with skirt
Stock cylinder skirt bored off......
Everybody takes the looks of the seemingly stock 110cc with whaat appears to be just bolt-on mods lightly until they get smoked badly and couldn't seem to understand how....LOL