I would first check the oil for fuel contamination. At times, the float valve doesn't quite seat due to debris or a worn tip- and fuel continues through and floods the engine. The thinned oil will make them smoke nastily. So, check the level and give a whiff. Too much and the fuel smell indicates the above. If all is ok with it breathing white smoke- I would suspect a failed cylinder head gasket leak.

"he only used it on his personal property"...I've found that many people don't tell the truth when they're trying to sell something.

I wonder if he was also selling a car that his mother drove once a week to church on sundays? Yes check the oil for contamination and proper level. If that checks out then it is time for cleaning the fuel system and a carb rebuild.

"If all is ok with it breathing white smoke- I would suspect a failed cylinder head gasket leak."

Agree.

Walt Conner

Thanks everyone for the quick replies. It's been raining here, and haven't had a chance to check for gasoline smell in the oil.

How big a deal is a carb rebuild, typically? Something I can probably do myself if I'm mechanically inclined, or too tricky to get right?

I don't have a trailer to take it to the shop, so I'd rather diagnose and resolve the issue on my own if possible.

Matt

All,

Thanks for the help on the diagnosis. Very strong smell of gas from the dip stick, so I'm going to check on the carb.

Any advice on the best place for parts or a tutorial on how to do this?

Thanks again!

Float got stuck on the slope. Change oil. Pick up mower and drop on carb side from about 6" height, Start up and see what happens. I find that the use of stabilizer/cleaner and marvel Mystery oil prevents this. OTOH, you might need a new float kit with inlet valve (needle and seat).

Better get some help to lift and drop it.

{{!gwi}}

Holy crap! I didn't know it was that big. Yeah, I guess that's not going to work too well. Hell, take the engine off and slam it down a few times. It's a stuck float. That means, use your imagination; improvise and overcome!

Or clamp fuel line, remove the bowl from the carb, then needle & seat, flush, reinstall.

I knew you didn't know how big it was when you posted, saxman. Actually one man might be able lift the front end because most of the weight is toward the rear of the machine. The reason I commented about people not telling the truth is because even though these are great machines, many used ones have seen many hours of service.

Tap carb bowl with screw driver handle, install gas line shut off valve and use it when engine is not running.

Walt Conner

My problem is the definitions. We 'walk behind' any mower that's not some kind of rider, and Toro for example calls a regular mower a 'walk power mower'. I just didn't know what it was or I wouldn't have made the suggestion to lift/drop it to shake the float loose. Then you have plenty of posts here about 'mowers' or lawnmowers' that turn out to be riders and should be posted in the 'tractor' forum. Kind of a mess.