A gas leak can be a dangerous situation that can lead to a fire. You could come out to the garage and smell gas and find a puddle under the lawn mower. The first thing to do in that situation is turn off the gas at the shutoff if it has one and then push it outside. You don’t want to take the risk of it catching fire in a garage or outbuilding.
Gas line connections are a common place where leaks occur. Gas line fittings in the bottom of gas tanks and gas filters are areas that commonly leak.
The lawn mower can also be leaking from the carburetor. The needle and seat is where the leak develops as the needle does not seat properly. Fuel then goes through the carburetor and into the cylinder of the engine. Then the gas will seep past the piston and into the crankcase and can fill it up to overflowing.
Your next step should be to take your lawn mower to a repair specialist who can properly diagnose this problem and resolve it. Gas leaks are a serious safety hazard and with some lawn mowers holding several gallons of gas, you don’t want to chance making a repair that might fail and cause a fire.
By inspecting your lawn mower each time you use it, you can catch that gas drip before it turns into a full blow leak. My lawn mower is leaking gas is a serious situation and should be remedied quickly.