Troubleshooting your Lawn Boy front-engine lawn tractor when its deck vibrates
If the mower vibrates when you engage the cutting blades, there might be a problem with the blade drive system. Deck vibration can be caused by an unbalanced blade, worn pulley or mandrel, bad blade belt or debris caught inside a pulley. Loose nuts or bolts on the pulleys, mandrels or blades can also cause vibration. Remove the mower deck and re-tighten all fasteners. Check for wear on pulleys, mandrels and blades. Replace any worn or damaged components.
How to fix your Lawn Boy front-engine lawn tractor when it won't move
Replace the ground drive belt if you find it worn or broken when the riding lawn mower won't move. If the engine dies when you release the brake, then the seat switch may be unplugged or broken. Our troubleshooting video riding lawn mower engine dies when you release the brake shows how to check the seat switch. Replace the seat if it's damaged and won't activate the seat switch.
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 riding mower the first time and after any transaxle repair. Tune up the mower 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 riding mower.