Do It Yourself Repair: Lawn Mower Engine Problem Troubleshooting

Here are some symptons and probable causes of lawn mower problems to help you troubleshoot, repair and prevent.

Lawn care season is upon us. Is your lawn mower ready? Improper maintenance is the biggest cause of lawn mower engine problems. Here are some problems that can arise with your lawn mower and what could be causing them.

There are several things that can cause a lawn mower to lack power. The first thing you want to check is your gas. If you are starting a new season with last year's gas, then your gas is too old. It would need to be replaced. Old engine oil can also have this effect. Bad spark plugs can cause a lawn mower to lack power. These would also need to be checked. Replace them if needed. Check your lawn mower's air filter. Make sure it isn't overly dirty. Replace it if needed. Make sure your lawn mower is properly lubricated. Check to see if piston rings and valves are sealed properly. The choke should also be checked. If it is clogged, it will need to be cleaned. A blown or worn head gasket can also cause a lawn mower to lack power. If your lawn mower is lacking power, check these possible causes.

An engine that isn't mounted properly can cause a lawn mower to vibrate. If the counterbalance isn't timed properly or if the crankshaft is bent, it will vibrate. These conditions may require you to service the lawn mower. If there seems to be too much of a vibration in the engine, check these as possible causes.



If your engine knocks it could be overheated. You should check the connection rod and flywheel to make sure they are secure. A buildup of carbon can also cause overheating. This can usually be cleaned. You should also check cylinders and the carburetor setting.

Some engine problems can cause a lawn mower engine to die after it has been started. First, make sure you have plenty of clean fuel. Check the muffler. If it is clogged, it will need to be cleaned. Check the air filter. If it is dirty, it may need cleaned or even replaced. Check the shut off valve. Make sure it isn't closed. The fuel tank vent could also be blocked. This may need cleaned. A bad carburetor can also cause a lawn mower to die. If it is bad, it may need serviced or replaced.

What if the lawn mower just doesn't start at all? First, and most important, make sure there is fuel in it. It could also be a flooded engine. Try turning off the fuel and then starting the engine. Once it starts, turn the fuel back on. Make sure that you started the lawn mower on the right throttle setting. Emptying the fuel tank and then refilling is also a good trick. Sometimes water gets into the tank and this can cause it not to start. Again, make sure you are not using last year's gas. Old gas can also cause the engine not to start. Replace it if needed. Make sure the terminal covers have not worked loose. They should be placed tightly over the spark plugs. Try cleaning the spark plugs. If they are defective, replace them. Make sure your ignition switch is on. Some lawn mowers come with a cutoff switch as a safety device. If this is defective, it can cause the mower not to start. This may need replaced.

If you have your owner's manual, refer to it for repairs. Always follow safety instructions. Lawn mower repair by a professional can be expensive. However, if you are unsure of something, it's best to seek help.

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