Lawnmower smokes

[Wade Lippman]

I have a Craftsman push lawnmower. It is about 6 years old and starts on the first pull without priming or choke. Very satisfied until last week.
Last two times I used it, it smoked badly for a couple seconds and then stopped. Stopped smoking I mean; it ran fine.
I assumed it was burning oil, but the level is where it was when I filled it a few months ago.

Any idea what might be going on? Anything to be done about it?

I only use it to cut about 1000sf; when it breaks I intend on getting an battery powered one.

[Tom M King]

Did it get tipped up to change the blade or anything?

What color was the smoke?

[Chris Padilla]

Nicotine patch?

[Phil Thien]

I have a Craftsman push lawnmower. It is about 6 years old and starts on the first pull without priming or choke. Very satisfied until last week.
Last two times I used it, it smoked badly for a couple seconds and then stopped. Stopped smoking I mean; it ran fine.
I assumed it was burning oil, but the level is where it was when I filled it a few months ago.

Any idea what might be going on? Anything to be done about it?

I only use it to cut about 1000sf; when it breaks I intend on getting an battery powered one.

You're lucky yours starts at all.

I'm going to get a battery powered one, too.

FWIW, I once overhead a convo about a bottom seal at the small engine repair place. They go bad after a while and the owner was told it would smoke a little more and a little more until it would be a hard starter.

[Bill Orbine]

Usually not much can be done.....considering that this generation mowers are tossed out when broken. The cost to repair would justify buying a new mower.

Oil is bluish, water is white/grey and gas is black. I don't know what color nicotine patch would be:rolleyes:. What color is the smoke?

[Bruce Page]

You're likely getting a few drops of oil seeping past the rings as it sits between uses. I wouldn't worry too much about it but keep an eye on the oil level.
Is it an OHV engine?

[Tom M King]

I have a twenty year old pressure washer. It had an 11hp B&S motor that was always a pain to start. The last time we ran it a year or little more ago, it worked fine, and was working fine when we ran the gas out of it. A couple of weeks ago, wouldn't start. Had spark, getting fuel-nothing. Checked compression and it's 28.5 psi.

My nephew told me he had a pressure washer that someone had given him years ago. They had let it freeze, and it ruined the pump. Mine was a much better quality washer, so he gave me the motor. He said it hadn't been started in years. It had a 13 hp Honda old enough to have the hp listed on the motor, and was the right shaft size and mount matched up perfectly. We poured the old gas out, put in fresh non-ethanol, and it started on the first pull. It's started on the first pull every time since. I felt like I had Rich Riddle's luck.

[Bert Kemp]

Honda motors always start easy they are tops.


I have a twenty year old pressure washer. It had an 11hp B&S motor that was always a pain to start. The last time we ran it a year or little more ago, it worked fine, and was working fine when we ran the gas out of it. A couple of weeks ago, wouldn't start. Had spark, getting fuel-nothing. Checked compression and it's 28.5 psi.

My nephew told me he had a pressure washer that someone had given him years ago. They had let it freeze, and it ruined the pump. Mine was a much better quality washer, so he gave me the motor. He said it hadn't been started in years. It had a 13 hp Honda old enough to have the hp listed on the motor, and was the right shaft size and mount matched up perfectly. We poured the old gas out, put in fresh non-ethanol, and it started on the first pull. It's started on the first pull every time since. I felt like I had Rich Riddle's luck.

[Wade Lippman]

Did it get tipped up to change the blade or anything?

What color was the smoke?
The smoke is light gray.

I tilt it at about 45* twice every time I use it to get it from one place to another and back, but I have been doing that for 2 years now without smoking.

Don't know about OHV, but it doesn't say that anywhere, so I assume not.

[Tom M King]

Maybe it had some water in there somewhere that ended up getting run through it??????????? Sounds like water smoke. Anyway, if it's not smoking now, keep running it as long as it lasts.

[Randy Rizzo]

Honda motors always start easy they are tops.

there's always a fly in the ointment. I had, still have a Honda snowblower. Engine began to surge all the time, finally got fed up and took it in. The governor was screwed up. And in order to fix it the portion of the governor broken was internal,the engine case would have to be split to fix, repair estimate was north of $300. Told em I run it that way til it blew up, I paid less than $400 for the whole unit new. I had also thought Honda's were bullet proof

[Tom Stenzel]

My FIL bought a new self propelled mower and gave us his old Craftsman mower. Don't know how old it is but it's been around long enough to have a Tecumseh engine on it. When we got it it would give off a good puff of blue smoke on startup. I thought it wasn't going to be around much longer.

12 years later... and it still gives off a puff of blue smoke on startup.

Yep, any time now! ;)

I can't push the mower anymore to run it but still have to FIX the thing when it's on the fritz. Earlier my wife was cutting the grass when she hit something and stalled it. Next thing I know, it's in front of me cause it won't start. Pulling the cord I found no compression. None. I thought for sure it was done for. Pulled it apart to do the autopsy, found a chunk of ash had broken loose in the combustion chamber had gotten caught under the exhaust valve.

Soon it was back to running like used again!

-Tom

[Dan Hunkele]

I second Bruce's reply. Just make sure the oil level isn't overfull.

[Pat Barry]

Maybe it had some water in there somewhere that ended up getting run through it??????????? Sounds like water smoke. Anyway, if it's not smoking now, keep running it as long as it lasts.


How are you getting water in a lawnmower engine? I bet its oil smoke. If its bad the sparkplug will be showing evidence of oil. Add oil as needed adn run that thing til it quits.

[Mike Henderson]

My experience with small engines - not recent but some years ago - was that the rings/cylinder is where they start to fail. Many of the older small engines had a splash oil delivery system. A small "dipper" was put on the bottom of the connecting rod - it was put on with one of the connecting rod bolts - and it splashed oil around in the engine to lubricate things. The bottom of the connecting rod had an open place so oil get get to the bearing surface.

But this approach did not do a good job of oiling the cylinder walls and eventually the rings wear. When that happens, you start getting a lot of blowby and the flow of combustion gases through the crankcase often caused oil to be blown through the crankcase breather. Eventually, the oil was depleted and connecting rod would seize up on the crankshaft.

Anyway, may not be the problem but it's about all I know about small engines.

Mike

[Wade Lippman]

Started the mower again today and it didn't smoke at all. Nothing has changed, it just didn't smoke.

I didn't mention it the first time (didn't want to confuse anyone) but I added something called "Mechanic in a bottle" just before it started smoking. Before asking here I asked them if they could be responsible. I thought maybe it had loosened up some crud that caused smoke. They said their product couldn't cause smoke; it was either oil or a carburetor problem.

But whatever it was, it seems to be gone now.

[Andre Packwood]

+2 on Bruces's reply. I also have a Craftsman mower with a Briggs and Stratton engine. My neighbor also uses it and at some point, he added too much oil. I guess that was the source of the oil that soaked the air filter, blocking the passage of air and making the engine very hard to start, and if it did start, it would sputter and stop. There was also oil on the parts past the filter. Although the smoke in this case was black (too rich gas/air mixture) instead of gray, it shows that too much oil can be a bad thing.

The filter on this mower is also prone to be doused with water (rain or hose) as well as blocked by dirt, especially if you run the mower over dry, barren terrain. The location of the filter is not ideal, in my opinion.