It is not unusual to see a red-faced gardener, building up a sweat, pulling and pulling again at the starter cord with no result.
The cause might be a burnt plug or a clogged filter, but is most likely the wrong fuel — and not taking the proper care of the fuel during down time is the cause.
The petrol for your lawnmower must be unleaded, the octane must be a minimum of 87, and if it contains ethanol this should be no more than 10%. Very important, the petrol must be fresh. Most people don’t know that fuel can become stale.
Two-stroke engines will use a mix of high-octane petrol and special two-stroke oil in the ratio of 50 parts petrol to 1 part oil. To be safe, check the manufacturer’s instructions. This mix should be done in a container, not in the tank of the mower.
When petrol is exposed to air or direct sunlight it begins to break down and becomes “stale”. Always store petrol in a clean, approved plastic container out of the sun. Should the mower be standing idle for 2 to 4 weeks, fill the tank after use to minimize the volume of air in contact with the petrol. Turn the fuel valve to the OFF position and start the engine. Leave it to run until it cuts out, thus cleaning out the whole system avoiding petrol becoming stale in the engine.
If your mower is going to be standing for extended periods you may want to consider using a Fuel Stabilizer. There are various brands on the market, such as Briggs & Stratton or Honda, and each has its own formula for mixing so follow their instructions. Remember that these fuel stabilizers will not refresh stale petrol.
As mentioned, if the petrol has an ethanol content, we want to limit this to a maximum of 10%. Anything more will cause corrosion and attract water. This will make it difficult to start the engine, it will probably be running rough, and could damage the engine and void the warranty.
Some other good tips to keep your mower running smoothly and avoiding the frustration of difficulty starting or running rough:
- Clean the filter, this is a simple task and will save a lot of wear and tear on the motor.
- Check the spark plug and change it as soon as it shows signs of carbon. This with clean fresh petrol will ensure smooth running action.
The rules are fairly basic and straightforward. Always use fresh, high-octane petrol, mix with oil in the correct recommended proportions. Do not keep it for long periods in storage, store it in a clean plastic container out of direct sunlight. During long periods of down time, remember to switch the fuel valve to “OFF” and run the system dry through the engine.
Push and self propelled lawn mower engines are fairly robust. They normally work in dusty conditions and are often abused and not taken care of as they should be, but a little TLC can help immensely with longevity.