What could be causing a lawn mower to back fire?

Answer by  babyhueyk (96)

You need to check the key way.To do this requries the removel of the fly wheel.You will have too take the shroud off and then remove the cluch bearging. Now you can lift the fly wheel off.You may have to use a screwdriver under it to pry it off . Now check the key. If it is bent Replace it.

Answer by  carryvan (148)

If your lawn mower only backfires occasionally, I would not worry about it. Sometimes your lawnmower can backfire if the spark plug briefly loses a spark either from a sharp influx in fuel or an electrical glitch.

Answer by  Angelis (40)

It could backfire due to a faulty spark plug that needs to be replaced. It could also backfire because the wrong grade of gas is being used, which could cause pre-detonation. Finally the last most common reason is because the valves on the lawnmower's head need to be adjusted.

Answer by  Rob900 (4)

There is no worry about it blowing up, like in the movies. You should take it in to be serviced (tune up)

Answer by  Chiyamaka (846)

There is probably a problem with the engine. I recommend that you stop using the lawn mower, there is a risk of explosion. Bring it to a local service station.

Answer by  Brandon55 (1719)

First, don't worry because your lawn mower will not blow up. Generally a lawn mower backfiring is caused by a fuel to gas imbalance. Try replacing your air filter and if you have a carburetor loosen the wing nut on top of it a little. Additionally, underneath the carburetor there is a needle, adjust it a little.