Is your lawnmower running for 5-10 seconds and then stopping? There are a number of things that could be causing this, the first thing you'll need to do is check out the following things:
- What make & model your lawnmower is
- If it's a fuel based lawnmower, double check the fuel tank.
In most cases where a lawnmower stops working, then some sort of fuel issue is usually behind it.
Here's the most common case I've come up against in my time:
Things that will make your lawnmower stop working
Have you tried removing the fuel tanks cap and turning the engine on to see what happens?
If the engine runs as normal as soon as the fuel tank cap is removed, then the vent hole could be blocked up in some way.
Try clearing the little airing holes found on the cap, or replace it with a completely new one and see if that does the trick.
The main thing you'll want to do is make sure flow of air is travelling freely into the tank when the cap is off. Air should flow freely for at least one minute.
If this is not helping solve your problem, then you need to check for any other possible fuel related problem.
Fuel problems with lawnmowers
Another common issue is that fuel is somehow not getting into the carburettor or travelling into the carb from the fuel tank.
Here's a more extensive list of lawn mower problems people often face, that you might want to investigate in more detail:
- Lawn mower has unsecured or unconnected spark plug (keep an eye out for dirt or debris)
- Fuel not reaching your lawn mower's engine
- Air filter issues