Push mower running unevenly, making soft popping sounds?

Question

I have a brand new Murray push mower with a Briggs and Stratton engine, only 5 or 6 hours of use so far. The past day or so it has become harder to start, and runs unevenly the first 5 minutes or so. Once it settles down and I try to use it, sometimes it will begin to run unevenly again and I get a popping sound on the side of the engine near the primer bulb. It doesn't always do this, sometimes it runs normally, and sometimes when this happens I can shut it off and let it sit a while and try again, and it operates as it should.

Any ideas?

Briggs &amp; Stratton · Accepted Answer

First, you should do your break-in oil change. This should be done after the first 5 hours of use. Next you will need to make sure the fuel is fresh, less than 2 weeks old. Stale fuel can cause backfiring like you are getting. You will also want to check the choke on the engine. If it is not functioning it will also cause this issue.

? · Answer

I agree with Tex take it back. Buy a new mower without a Briggs and Crapton.

princess pounder · Answer

$100 mowers do that, mine does and still runs 10 years later.

john · Answer

It sounds as if you have a loose carb, or a hanging valve. I would return and replace it. This engine was not assembled correctly.

Redneck Texan · Answer

With only five or six hours of running you should take it back, it is definitely still under warranty.

Push mower running unevenly, making soft popping sounds?

5 Answers