I own a John Deere L 120 Mower It presently has slightly more than 500 hrs on it. It cuts about 1 1/2 acres of gently rolling landscape. For about six weeks ago it started losing pulling power on inclines about 30 to 45 minutes into after beginning the cut. L went to see the local Deere dealer and he said unequivocly that l had purchased the wrong mower for my application and it was the transmission and it would cost in the neighberhood of $900 to replace it. I did purchase a new belt while I was there and replaced it the next week. It improved the performance,but only slightly. Under any kind of load (mower deck ,cart loaded with brush,or leaf broom) It loses power on inclines after less than an hour of operation. Before a I spend the money to repair or replace this mower I'd like to get some other opinions.

Bucktoo

This is basically telling me that the governor isn't doing it's job and it's a governor, fuel, air carb problem.

Start with the governor. Make sure it moves freely and there are no leaves around it.

If it happens again, remove the air cleaner temporarily and see if it will do the hill.

Then look at carb/fuel system.