Lawn Mower Leaking
Gas from Air Filter
A hot mower leaking gas obviously isn't safe especially if you store your mower in a garage attached to the house. This is a problem that needs to be taken care of right now.
So why does the lawn mower leak gas from the air filter? The most common reason the mower leaks gas from the air filter is because it was tipped over with the carburettor side facing down. But there are other possible reasons:
- Choke sticking
- Worn float needle
- Gas bowl seal worn
- Perished gas line
- Gas tank cap damaged
When a mower clogs with grass it's very tempting to just tip it over and clean it. This unfortunately allows fuel to get into places it shouldn't. If the mower is tipped over with the carburettor side down, gas will flood out of the carburettor and soak the air filter.
You may also find the mower hard to start, running rough and often blowing black smoke. This is a sure sign that the air filter is soaked in gas. The fix is simple - remove and replace the filter.
A gas covered filter will cause the engine to not run, run rough and often with black smoke.
Simply replace the filter.
Tipping your Mower Over
Pull the plug wire before working on your mower, it prevents accidental starting.
If fitted to your mower, turn it off when mower not in use and before starting any maintenance.
You can tip your mower up like this by hooking the handlebars under a bench.
If you prefer tipping your mower to the side, that's fine just be sure the carburettor side is facing up.
The carburettor side is the same side as the air filter.
What Is A Float Needle?
The float and needle control gas supply to the carburettor.
The tip of the needle is a seal and when worn turn pink. On some engines the seal is embedded in the carburettor needle seat.
When the float is in the dropped position gas should flow steadily.
You can check the float and needle by removing the fuel bowl and lifting the float up, the gas should stop flowing.
If it doesn't - replace needle/seal or the whole carburettor.
Is The Choke Sticking?
When the choke is in the off position, the choke plate should be completely open.
Removing just the air filter will allow you see the choke plate.
If yours isn't opening, adjust cable or if yours is auto choke, check for binding.
What Is The Gas Bowl?
The bowl seal will leak if pinched, so care needs to be taken when refitting the gas bowl.
The seals become perished over time also.
Checking The Gas Lines
Check the line for cracks and leaks. Replacing gas line is an easy repair.
Bear in mind gas line comes in different sizes, so measure the inside diameter (id) of the old line before buying.
Leaking Gas Tanks
Tanks are pretty durable, but if left in direct strong sun can damage them.
Poor fitting or damaged gas cap will leak. A gas cap must be vented.
Lawn mower leaking oil from the air filter? The most common reason oil is leaking from a lawn mower air filter is too much oil in the engine, but it can also happen when the mower has been on its side.
Lawn mower leaking gas from the primer bulb? The primer bulb is perished and has split, mice like to eat them also. Remove the primer bulb retaining ring and replace the primer bulb.