Having a faulty Yamaha Piston and Ring Assembly is like trying to get the last bit of whipped cream out of the can. There is just not enough gas left to push the sweet treat out of the can. We know it's tempting, but the nozzle is not a straw. Your engine builds pressure in the cylinder, which the caddie needs to push its weight. The lower the pressure, the less performance you will have. The typical four-cycle coach should hold about 140 pounds per cylinder or better. All kinds of things can contribute to this issue, so make sure you get everything you need when you call to order.Low-end torque is one of the most important things you can have if you use your caddie for work purposes. Being able to climb that hill while pulling a heavy load would make life so much easier. Grap a compression gauge from your local auto parts shop and see what you have. If you are low, this could explain why you are having problems. Next, try taking a spoonful of the same oil you use in the engine and dump it right in the spark plug hole. Now take another compression reading and see if it comes up drastically. If it does, you are on the right track. If you reassemble it and try to run it after doing this, you will not hurt anything. You may even get better performance until that oil burns off. It will smoke like a mosquito truck, though.This is not a hard part to replace if you are familiar with this type of work. However, we would recommend that you have a friend over to help. You may also want to consider a Yamaha OEM manual to walk you through the process. Finally, give Buggies Unlimited a call and get everything you need.