I just had the motor rebuilt. It would start fine, when I started out of the hole there was no power and the motor was missing bad. The shift switch was not working. I replaced the switch, the motor runs better but is still missing out of the hole and is lacking power. B4 the rebuild there was power to spair and top speed was 72mph, now it bearly gets out of the hole and top speed is 55 and top RPM is 50,000. At times you can feel it wants to go like it should. I changed all fule filters and plugs with on help. I also checked compression and it is fine. What should I try next?