I am trying to trouble shoot my craftsman ridding mower. When I go up hill it just doesn't have the power it use too. this is only the 5th mowing season for it. I have replaced the belt, spark plug and the air filter and changed the gas out. But it almost feels as though it is in the drive somewhere but I'm not sure. Please help.

 

If I understand this right, the engine is still running like it should be, but the mower is slower than it used to be uphill? If so...is this a hydro or standard tranny?

 

Correct, the engine is still running like it should be, but the mower is slower than it used to be uphill. I believe it is an automatic hydro tranny.

 

You stated you replaced a belt, which one? Was it the tranny belt? If not, you need to have a close look at it and determine if it is the cause of your woes. If you did then you need to look at the cooling fins and cooling fan to see if you have a potential overheating issue with the tranny. Overheating of the hydro oil causes cavitation of the oil and renders it ineffective.