There are many practical maintenance-related reasons for tilting a lawn mower on its side. Running a lawn mower on its side, however, comes with inherent safety risks and not all lawn mower engines would run when positioned in this fashion.
Tilting a lawn mower on its side requires being familiar with the location of the mower’s carburetor, exhaust, and fuel opening. Their location dictates on what side a lawn mower can be safely tilted. The feasibility of running a lawn mower on its side depends on the type of engine it has.
This article will provide you with essential details about tilting a lawn mower on its side the correct way. It will also inform you about why not all lawn mowers would run while on their side.
Why Most Lawn Mower Engines Will Not Run on Their Side
First, it is important to note that running a lawn mower on its side exposes anyone near the spinning blades to the risk of severe injury. This can be from coming in contact with the running blades or by being struck with projectiles that the blades might cast into the air.
Vertical Shaft and Horizontal Shaft Lawn Mower Engines
If informed of the risk you still wish to attempt to run a lawn mower on its side, you need to know what mower engines have the capability of doing so. The first determining factor is whether the mower engine is equipped with a vertical or horizontal shaft.
Only mower engines with a horizontal shaft can run for a sustained period on their side. Those with vertical shafts cannot. Also, the mower’s design and the placement of the carburetor and the crankcase may impede either type of engine from running on its side without causing potential damage to the engine or creating the risk of a fuel or oil fire.
This is why hobbyists who repurpose horizontal shaft lawn mower engines for go-karts and other projects usually have to reposition the carburetor and other components for optimal performance.
Two-Stroke and Four-Stroke Lawn Mower Engines
The second determining factor for the feasibility of running a lawn mower on its side is whether it has a two-stroke or four-stroke engine.
A two-stroke engine can run on its side because it does not require an oil reservoir. Two-stroke engines are lubricated by adding oil directly to the fuel mixture. Therefore, placing them on their side will not cause a loss of oil circulation.
Since a four-stroke engine does have an oil reservoir, being on its side will cause the oil in the reservoir to pool on one side. It will be unable to reach the crankshaft, and the engine will lose vital lubrication, causing it to seize up if run while on their side.
Can You Tip a Lawn Mower on Its Side?
If you intend to tilt a lawn mower on its side to conduct maintenance and not run its engine, doing so is relatively safe.
Most lawn mowers, however, should only be tipped onto a specific side. Doing otherwise will not permanently damage the lawn mower, but it can result in unwanted fuel and oil spillage in addition to other inconveniences.
Here are the most common things that can happen if you tip a lawn mower to the wrong side:
- Tipping a lawn mower to the wrong side can saturate the air filter with fuel. If the type of air filter used by the lawn mower is paper-based, you will have to replace it if fuel comes into contact.
- The spark plug can become contaminated with fuel or oil. Usually, removing the spark plug and wiping it clean before inserting it back in the mower rectifies this problem.
- The combustion chamber can become flooded with fuel. When engine flooding occurs, the mower may not crank over when you want to start it after placing it back in its upright position. This is called hydro-locking, and it happens when the chamber fills with gas. Removing the spark plug releases the trapped gas and remedies the problem.
- Black or white smoke may be released when restarting the motor. This may appear ominous, but it is normal. It will stop doing so after a few minutes.
Unplug or Remove the Spark Plug Before Tipping the Mower on Its Side
As a precaution, to prevent the engine from accidentally being engaged while the mower is on its side, it is recommended that you unplug or remove the spark plug from the mower.
This is especially important if you plan on working on the blades while the mower is on its side.
What Side Can You Tilt a Lawn Mower?
The definitive answer to what side you can tilt your lawn mower will normally be found in your mower’s owner manual. However, if the manual is not available, a good rule of thumb to follow is to flip the mower so that it is resting on the exhaust side. The carburetor should be facing upward.
Even when tilted on its appropriate side, the lawn mower can have a few failed starts when placed back in its upright position. White smoke might be visible as you restart the mower, although not as intensely as when you attempt a restart after it was on its wrong side.
Place Special Attention to the Fuel Cap When Tipping a Lawn Mower
It is recommended that you expend the fuel in the mower’s tank before flipping it on its side. This is to prevent fuel from leaking out of it.
If you opt not to run the fuel down before flipping it, be aware that most lawn mower fuel caps have a venting mechanism. This means that even though the cap is tightly secured, fuel can escape from the vent when it is on its side. A way to prevent this is to remove the fuel cap, place a sheet of plastic over the fuel opening, and then screw the cap back on over the plastic.
The addition of the plastic sheet will create a barrier keeping the fuel from channeling through the vent.
Do You Need to Tilt Your Mower on Its Side?
If you need to remove the mower blades or remove obstructions, there isn’t an alternative to placing the mower on its side.
However, if you are planning to flip the mower to drain the oil from the dipstick tube, other options are available.
Check if your lawn mower has an oil drain plug at the bottom. If it does, you can place a pan under the mower and drain the oil without the need of tilting it on its side.
Another option for removing the old oil is to use a powered oil extractor pump such as the UTSAUTO 12V Oil Extractor (link to Amazon) or the MANNEW 12V Oil Extractor (link to Amazon). Both are affordable and suction the oil out of your mower from a tube that you slide down the dipstick tube.
You could also use manual siphon pumps, such as the Wekster Siphon Oil Pump or the Briggs and Stratton 4-liter Oil Extraction Pump (links to Amazon). These are slower than powered pumps but can drain the oil out of your mower just as effectively.
Conclusion
The success of running a lawn mower while it is on its side will depend on the type of engine that it has. It is a dangerous task, and great care should be taken if attempting to do so.
Simply tilting a lawn mower on its side to conduct maintenance without turning on the engine is much safer. By taking heed of the recommendations mentioned above, you will minimize any potential issue that might arise by flipping a lawn mower.