Old 05-14-06, 09:53 AM
Thread Starter
Join Date: May 2006
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Question Backfire

Hello there.

I have an MTD riding lawnmower 42" cut 16.5 hp Briggs and Stratton. The mower runs fine except that it consistantly backfires upon shutting down. I have replaced plugs, air filter, fuel filter, and oil (standard maintence). Additionally, when you turn the key it pauses before starting, like trying to force myself out of the bed too early in the morning. Any ideas???
Old 05-14-06, 12:47 PM
Join Date: Jul 2004
Location: Ohio
Posts: 16
Likes: 0
Received 0 Likes on 0 Posts
Let the engine idle for half a minute before turning the key off. Shutting it off at full throttle will often cause a backfire. As for pausing when old is the battery? You're lucky to get 5 years out of most lawnmower batteries nowadays, often less. Mine did the same before I replaced my battery. Check that all the connections are clean and tight. Make sure no one is leaving the key on.Simple stuff, I know. If more than 3 years old, consider replacing it. I also keep a 1 amp trickle charger around for just such things. Inexpensive and does the job, just takes longer.

Old 05-14-06, 11:40 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 17,996
Received 106 Likes on 96 Posts
The pause in starting sounds like it could also be indicating the need for a valve adjustment. This should be performed as part of yearly maintainence.
Old 05-15-06, 05:03 PM
puey61's Avatar
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,234
Likes: 0
Received 2 Likes on 2 Posts
You didn't indicate the year of the machine, but, this may be a model with a fuel shut-off solenoid and the solenoid may be defective, whereas it is stuck in the disengaged position and not doing its intended job. You will know if you have this solenoid if you see a single wire in the vicinity of the carburetor. If you are unsure, post back with chassis' as well as engine's ID numbers (all of them) and we'll check for you. If, this engine does not have one, do as AZ indicated...Idle down before shutting down. An older, thinning muffler will be more apt to bang than a newer one, by the way.

Thread Tools
Search this Thread
Ask a Question
Question Title: