Loss of power on a 02 ezgo st 480

[crazyhorse]

I have almost completed the modifications on my 02 ezgo st480, lifted front 2 inches, added 12" wheels w/23" tires. Painted entire cart, recovered seats. My problem now is that the cart doesn't seem to have much power. It also will continue to run for several seconds after letting off the accelerator. This make it hard to change from drive to reverse quickly. It also spits and sputter when you stop cart and start out again. I have read several post about the governor and throttle adjustments, could this be my problem or is it something more serious? I have also wandered about going to the shorter belt for increased low end torque, but with the 28 degree clutch is this needed? I appreciate your knowledgible opinions! Thanks, sam