Lawn Mower Runs for about a Minute, then Shuts Down


Old 06-24-15, 10:52 AM
Thread Starter
Join Date: Apr 2011
Location: USA
Posts: 233
Received 0 Votes on 0 Posts
Lawn Mower Runs for about a Minute, then Shuts Down

My son is trying to repair a neighbors mower, but having some issues figuring out what's wrong. He's pretty good with repairing/maintaining mowers, but having an issue figuring this one out. If a make and model helps, I can provide, but I figure most small engines are basically the same.

The mower starts up without issue, and runs smoothly for about 60-90 seconds, then shuts down. He has cleaned the carb, and replaced the thermostat. Filter and plug looks good. Any idea what else might be wrong?

Thank you
Sponsored Links
Old 06-24-15, 11:39 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 23,448
Received 595 Votes on 549 Posts
Knowing what specifically he's working on would help a lot. You said he replaced the thermostat. Is it a liquid cooled engine or is the thermostat on an auto choke mechanism?
Old 06-24-15, 11:51 AM
Join Date: May 2015
Location: USA
Posts: 3,138
Received 2 Votes on 2 Posts
I'd put an inline spark tester on it to see if ignition is cutting out. Does it have a low oil shutdown? I'd check that too. Does it restart right away? If not, how long do you have to wait? If it restarts quickly, I'd be thinking fuel obstruction...
Old 06-24-15, 12:01 PM
Join Date: Jan 2013
Location: U.S.A.
Posts: 2,079
Received 67 Votes on 61 Posts
I agree that more information would help. Meanwhile, starting at the easiest, I would check the fuel cap to make sure that is clean and that the vent is not obstructed. After that, did he disassemble and clean the carburetor, or simply spray something into it? The latter seldom gets to where it needs to be.
Old 06-24-15, 12:24 PM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,981
Received 53 Votes on 43 Posts
My guess would be fuel. For whatever reason the fuel is not flowing freely into the float bowl. You can try removing the air filter and when it starts to cut out give it a little squirt of carb cleaner down the throat. If it recovers momentarily, fuel starvation.
Old 06-24-15, 12:24 PM
Thread Starter
Join Date: Apr 2011
Location: USA
Posts: 233
Received 0 Votes on 0 Posts
It's on an auto choke mechanism. I'll get more details if needed, but it's just a Craftsman 6.75 walk behind mower.
Old 06-24-15, 12:47 PM
Join Date: Jun 2006
Location: United States
Posts: 2,463
Received 11 Votes on 11 Posts
Please post the model number so we can see what engine it has. Have a good one. Geo
Old 06-24-15, 07:29 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 17,489
Received 44 Votes on 39 Posts
Reach the choke linkage and close it by hand when the engine starts to die. Does it keep running then?
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title: