Is your mower making a strange noise? As the mowing season draws to a close, your mower has more and more hours put on it since its spring service, making it more likely that something will need attention. Finding the source of noises and correcting them now can help you avoid costly repairs later on.
Honda makes some of the quietest small engines on the market, but they still produce enough noise to cause hearing damage. Hearing protection should be worn when using a mower just as you would with any other outdoor power equipment, but added noise may be a cause for concern.
If everything seems fine and the engine is just unusually noisy, check the muffler. Before pulling it off of the motor, wait at least a half hour after running the mower to let it cool down completely. Inspect the muffler for holes, and make sure the seal between the exhaust and the engine is intact.
While most greased components are sealed, other areas may occasionally need a light oil or silicone lubricant applied to keep them moving freely. This includes the controls, cables, wheels, and the handle, both where it bolts to the mower and where it folds for storage. Squeaking noises from the engine can be caused by grass and debris packed against the flywheel or engine shaft, or it could indicate a slightly bent shaft.
Some models have sealed cables and wheel bearings which won’t need to be greased. If the squeaking is coming from one of these wheels, spin it to make sure it’s moving freely. If it’s not, the wheel will need to be replaced.
Engine vibrations can loosen bolts and nuts over time. Go over your machine and check the tightness of each fastener. Here’s where to check, from the most likely to the least likely source:
– Muffler cover
– Engine cover
Some vibration is normal, but excess vibration is usually tied to the mower blade. Remove the blade from the mower and check for bends and cracking; if either is present, the blade needs to be replaced. To check the balance, hang the blade on a nail by its center hole. If one side sits lower, file off a little of the surface until the blade sits even on the nail.
Honda’s MicroCut system uses two blades and a set of washers that need to be installed in a specific order to prevent vibrations. The small blade should be put on first with the top flat edge pointing to the left, while the lower blade goes underneath with the curved ends pointed upward and the top edge to the right. There should be one washer between the blades and a second washer between the blades and the bolt.
The blade bolt on all mowers needs to be tight enough to stay on and prevent the blade from coming loose, but not so tight that it stretches the threads. Torque specs for this bolt can be found in the owner’s manual.
Even on engines equipped with Oil Alert, it’s a good idea to start with checking the oil, as a lack of lubrication can cause knocking and quickly lead to engine damage.
Light pinging is normal on engines under a heavy load, but if it occurs constantly, it’s probably caused by the fuel. If you’re running fresh automotive gasoline, it should have a high enough octane to keep this from happening, but its knock resistance can drop as it ages and degrades. Always use fuel within a month from purchase, or three months if treated with a stabilizer. “White gas,” commonly used in camp stoves, is gasoline, but it has a much lower octane rating. Even pouring a little from a leftover tank can reduce the fuel’s antiknock properties that it can cause pre-detonation.
If the fuel is fresh, check the ignition system. The spark plug should be clean and have the correct gap. If the wrong model of a spark plug is used, it can heat up to the point that it ignites the gas before the spark does. The coil may also need to be repositioned to change the ignition timing. Excess carbon build-up can also cause pre-ignition, but usually, this is only seen on motors that have been used for hundreds of hours.
Stop the Noise with Help from Honda Lawn Parts
As a certified dealer for Honda Power Equipment and Honda Engines, www.hondalawnparts.com can provide you with the parts you need to fix your mower, whether you just need a new blade or a major component. We ship across the U.S. and Canada.