100cc/81.33cc bbk tuning issues

[averageschmo1003]

Hi guys

I didn't want to post buts it's been weeks and I live in the middle of no where so I could use some advice. I have a 2008 peace sports night sky 4 stroke. Cheap Chinese scooter I recently put in the bbk. And now it only goes about 20, where as when it was a 50cc it went 40. It starts up good even runs good, going to do a plug chop Tonite. Timing is set correct I checked the piston when putting in the head. Valves clearance is set at .004 for intake and exhaust. new belt, new exhaust only thing I didn't do was new cam shaft and stator yet and that's on the way. Now I did do a new carburetor it is 18mm with a 88 main jet and 33 pilot ( pilot jet is the one that came with it I put in the 88) also did one of those cone air filters. Any advice would be great and any addition info I will supply if needed. Thanks hope everyone's having a good weekend.