Riding Mower and Tractor: Won't move
Check the ground drive belt and replace it if you find it worn or broken when the tractor won't move. If the engine dies when you release the brake, then the seat switch may be unplugged or broken. Plug the seat switch back in or replace it if it's defective. Check the transaxle freewheel control to see if the drive is disengaged. Shift the freewheel control to engage the transaxle if you find the control in the freewheel position. Purge air from the transaxle before using the tractor the first time and after any transaxle repair. Tune up the engine if it sputters and then stalls when engaging the drive system. Rebuild or replace the carburetor if it's clogged and not providing the engine with fuel to stay running when driving the tractor.
These repairs may help solve your Riding Mower and Tractor problem:
Replace the riding mower drive belt
If your riding lawn mower won't drive forward or slows down when you go uphill, check the drive belt. Reinstall the lawn tractor or riding mower drive belt if it's slipped out of place. Replace it if it's damaged or broken,
Replace the riding mower carburetor assembly
If the engine on your riding mower or lawn tractor is running roughly or only runs when the choke is partly on, you might need to replace the carburetor. The carburetor mixes gas with air before the fuel goes into the cylinder. If the gas/air mix isn't balanced, the engine won't have peak performance.
Rebuild the riding mower engine carburetor
The carburetor mixes fuel with air to create a combustible mixture that enters the engine cylinder and ignites to drive the piston. Impurities in gasoline can clog the carburetor. Seals and gaskets in the carburetor eventually wear out. Use a carburetor rebuild kit to refurbish a clogged or leaking carburetor.
Tune up the riding mower engine
The engine tune-up includes routine maintenance for a riding lawn mower or tractor. This tune-up includes replacing the engine oil, oil filter, air filter, fuel filter and spark plug. The tune-up also includes checking the ignition, carburetor, battery, throttle and choke controls, as well as cleaning the engine cooling fins.