Lawn-Mower-Problems

When it comes to mechanical things, lawn-mower-problems are as about as basic as you can get. Even if you don't know much about small engines, they're pretty easy to troubleshoot and most problems are pretty basic if you follow some simple directions. If you're like me and enjoy fixing things then please always think safety when working on any lawn equipment and always refer to your owner's manual.

Fixing these problems means working on gasoline powered devices that turn a limb cutting blade so please follow basic safety procedures. I know, pretty gruesome but I don't want anything to happen to you! Don't let the warning freak you out... for the handyman or woman, lawn mowers can be easily repaired by following a few simple steps.

DIY-Advice: You may read these safety tips and think... "What knucklehead would do that?" but believe me it's happened so please read and follow all safety precautions.

SAFETY (Read Your Owner's Manual)

• Lawn-mower-problems, as mentioned previously, has safety issues so always work on gasoline engines in a well ventilated area. Gasoline vapors are extremely toxic & volatile (explosive) so if you must work in your garage with the door closed then drain the gas into an approved gas can (gas cans are red in color) and let the residual vapors evaporate outside prior to beginning work. Same thing goes for solvents used to clean engine parts.

• When storing gasoline don't use those old rectangular thin sheet metal gas cans, believe it or not, they can collapse and expand with extreme temperature changes. Go out and purchase a newer sturdy plastic or round metal can. NEVER store gas in glass or especially plastic bottles, the gas can actually dissolve some plastics... ONLY USE APPROVED GAS CONTAINERS! Last but not least, never store gas containers where vapors can build up or near an open flame... do I need to explain why?

• I know this is some pretty basic stuff but I have to say it... please don't run the gasoline engine in a confined space. If your garage door is closed and you're running your gasoline engine you are poisoning yourself with carbon monoxide gas emitted from the exhaust of the engine... please only run the engine outdoors!

• When filling your lawn-mower with gas turn it off first. Let the engine cool prior to refueling since a hot engine could ignite the fuel if spilled on the engine. Please DON'T smoke while refueling... do I need to explain that one? OK, moving on.

The best way to avoid lawn-mower-problems is to perform periodic maintenance such as an oil change. When changing your oil, avoid contact to your skin since the used oil is toxic. Use heavy duty plastic gloves. Disposable ones are available at automotive parts supply stores or the big home centers. Please dispose of the used engine oil in a safe and responsible manner. Most automotive parts suppliers or repair shops will take your used motor oil at no charge so there is NO excuse for dumping it in the trash, down the drain, or in the ground.

• If the lawn-mower engine is running, avoid going near the spark plug wire. It's not a serious danger but the jolt you may receive may send you back into something you'd rather avoid. ALWAYS disconnect the spark plug wire and secure it away from the spark plug (better yet, remove the spark plug entirely) when doing any work on the engines moving parts (you know like the blade). Crazier things have happened so you don't want the engine starting on it's own. Even though it won't start now doesn't mean it won't start when your arm is compromised by the blade. In the case of a flooded carburetor, it corrects itself after a few minutes which could allow the engine to start so NEVER take chances.

Handyman-Tip: Newer mowers may have at least two systems to stop blade rotation. An "engine kill" and "blade brake", this is most likely a "dead-man" bar that must be held down for the mower to operate found on most inexpensive mowers. The second is a brake/clutch which enables to engine to run but stops the blade. The later is found on high end or riding mowers.

• NEVER under any circumstances should the dead-man bar be tied down unless the spark plug is removed. Even removing the gas tank isn't necessarily enough to prevent accidental starting. Many types of carburetors contain a float chamber which may still hold sufficient gas for several minutes of operation.

• 8. If you're working with older mowers (or other yard equipment) they may not have any modern safety systems or blade brake and only an interrupter contact for stopping the engine by shorting the spark plug terminal to the frame. These mowers are on a hair trigger and just rotating the blade can start them up when you least expect it.

Lawn-Mower-Problems... Engine Won't Start

"Mower will not start" - is the most common of lawn-mower-problems and is very often caused by the lack of maintenance. If it's spring time and your mower worked just fine last fall when you mowed your grass for the last time prior to winter setting in, the first thing to suspect is that the gas has gone bad. Drain the old gas and dispose of properly (please don't pour into the sewer system). Let's break down lawn-mower-problems into: Fuel, Air, and Spark (really the lack of it) to help you troubleshoot your problem.

Lawn-Mower-Problems Repair Tip: Keep up on the preventative maintenance and avoid most repairs. Check your lawn-mowers owner's manual for details.

Fuel Problems

This may seem like a silly lawn-mower-problems repair tip, but check your fuel tank to make sure you have gas. If the tank is empty... fill it and try again. If you have gas, then check the following:

• Check for closed fuel shutoff valve, fuel line, filter or fuel cap vent is clogged. Some fuel tanks may have a sediment catching screen where the carburetor supply line meets the fuel tank.

• If you've left you mower outside and exposed to rain... you could have water in the fuel. If the carburetor has a drain plug, operate it to rid it of the bottom layer which would have the water. If not, repeated pulling on the starter cord should eventually clear small amounts of water. Worse case, drain and begin with fresh gas.

• Carburetor is over-choked, Possibly flooded. Wait a few minutes and try again.

• Does your engine have a primer bulb? Does it feel like it's pushing gas into the intake pipe? Make sure the rubber hasn't dry-rotted or otherwise deteriorated. If many pushes still doesn't do anything, (and the previous steps have been done) the carburetor and fuel line may need cleaning.

  5. As stated in the beginning of this section, make sure you have fresh gas and not gas from last season. Old gas may work in an engine in good condition, but not so much in one that's seen better days.

Still Having Issues? Try this lawn-mower-problems repair tip:
Determine if fuel is reaching the cylinder: After a normal starting sequence the mower shows no signs of wanting to start, immediately remove the spark plug. The spark plug should be damp with gas with a distinct smell of gas from the spark plugs hole. If not, there could still be blockage in the fuel line or carburetor may need cleaning.

Air

If it just keeps running worse and worse until it stops (or doesn't start), it could easily be the air filter. Small engines need the optimal air/fuel ratio which is around 14:1. A clogged air filter can definitely change that optimal ratio. When starting a cold engine it's going to have to be a little lower which is why lawn-mowers have chokes. A choke plate restricts air intake which increases the richness of the mixture (more gas) being sucked into the cylinder.

Other types of lawn equipment (Most 2 cycle engines) and some lawn-mowers have a primer bulb to squirt gas into the intake pipe which augments the normal carburetor action. If you have no choke or primer bulb, your carburetor probably has a small gas reservoir which fills when the engine is off and provides that extra fuel when starting.

Too Much Air: An air/fuel mixture that is too lean (to much air) burns too quickly, and can result in engine damage over extended periods of operation. Follow these lawn-mower-problems repair tips below:

• 1. Make sure the choke isn't stuck in the open position.

• 2. The carburetor may need to be cleaned and/or adjusted.

Too Little Air: A mixture that is too rich (too much air) can cause a loss of power. It may even cause black smoke to from the exhaust which could be caused by other factors as well.

• 1. As stated in the beginning of this section... check the air filter. Remove the filter and see if the engine will start. However never run the engine extended periods of time without a clean air filter in place. Foam type filters may be washed and reused while the paper ones are most likely the through-away type.

• 2. Just like the section on too much air... too little air may be cause by the choke being stuck CLOSED. The choke is meant to be closed during a cold start, however it should remain open during normal operations.

• 3. Lastly, a bad carburetor can cause the air/fuel mixture to be too rich or too lean.

Spark and the Ignition System

A common lawn-mower-problem is spark... All internal combustion engines require a precisely timed spark during the compression cycle to ignite the air/fuel mixture we spoke about in the previous section on "Air". Testing to see if your lawn-mower is getting a spark is pretty easy.

Lawn-Mower-Problems Repair SAFETY... before performing this test make sure there is NO gas or gas vapor present that could be inadvertently ignited.

• Find yourself a small screwdriver with a well insulated handle. Remove the spark plug wire and insert the screwdriver into the boot or clip of the spark plug wire. Holding the INSULATED end of the screwdriver place the metal part of the tool approx 1/8 inch from the engine block or lawn-mower frame.

• Now, have someone pull the starter cord or turn the key and watch for a spark to leap across the 1/8 inch gap from the metal part of the screwdriver to the engine block. You should see the spark jump several times on each pull of the starter cord. Now... if you're NOT using a well insulated screwdriver for the test, YOU may feel the spark which is definitely a confirmation that the ignition system is working.

• Check the spark plug. Remove the spark plug using the proper socket and inspect it for damage or fouling. If the plug is light gray or brown with no carbon buildup, that's normal. The fuel/air ratio is correct and the engine doesn't appear to have any major problems. Look for excessive black carbon build up, that would indicate fuel/air mixture that is too rich (too much gas) or you may have the wrong type of spark plug for you engine (check your owner's manual). If you see damage to the spark plugs electrode, you may have the wrong plug installed, the mixture could be too lean, or the timing is set incorrectly.

• Recommended lawn-mower-problems repair here is to change the spark plug... they're cheap and your owner's manual probably recommends changing it anyway.

• If there is no spark, then there is a problem with your ignition system.