I'm having an issue with my huasheng 4stroke stock with 44t pinapple rear sprocket. Old one was great, hit about 28-35mph on the regular, slight knocking once in a while on inclines. New kit won't clear 22mph but runs smooth. Would like to hit 30 again though. First, everything ,bike and all kit setup is the same, but the new HS transfer case is a dual chain from bike berry. The old one was a single chain, didn't think it would make that big a difference. I got a flex poopoo exhaust and 40t rear hub sprocket, only increased from 20mph to the now 22 mph Max. Do the engines vary that much? Could it be just the dual chain trans vs the single. Any help to what would cause that mph difference would be great?