Craftsman mower never had a oil or filter change

[Trucku]

Bought my friends walk behind mower. He has had it for over 3 years and didn't use it anymore. It was smoking pretty badly because he put too much oil in the unit. When running, the mower shook baddy and shot out lots of smoke. He initially put in too much oil, because the mower was running badly. That was his fix

Anyway I took a risk with the mower and his snow blower(another story).

I didn't know where to start so I decided to give the mower a oil change.

I tipped the mower on its side to drain the oil and it poured out and looked like molasses.

I filled the engine with 20oz of Mobil 1 5w30, ran the motor for a few minutes and repeated this drain and fill another 8 times before I was happy. The oil finally pour out relatively clean before the last fill. The spark plug looks a little fouled, but the ultrasonic cleaner should bring it back to life. The air filter was filthy and soaked with oil I think. To clean the intake and cylinder, I sprayed seafoam into the carburetor while engine was running. I didn't allow the engine to die until after a good soaking. So I can test the mower, I used a t-shirt stretched across the filter housing to keep out anything big. Tomorrow I will buy a replacement.

After 2 hours the mower is running smoothly (plug not cleaned in ultrasonic bath yet), and with speed. It starts immediately and no longer puts or shakes.

My only concern is a slight hint of smoke. I don't know if it's just the exhaust or the mower burning oil. If the cylinder is leaking, is there anything I can add to the oil to stop it?
I don't want to take risks and cause any more damage to a neglected machine. Any help would be appreciated.

Thanks
Vishant

 

[RF Overlord]

Originally Posted By: Trucku
He initially put in too much oil, because the mower was running badly. That was his fix
Oh noes! Your neighbour has let slip the ancient secret to proper maintenance:

"If it's not running right, add more oil."

Now he'll have to kill you.

 

[SOHCman]

the smoke might just be left over oil in the breather hose/system?

 

[Cujet]

5w30 synthetic may be a little thin for an air cooled engine.

 

[Samilcar]

The manual for the B&S engine on our new walk behind mower calls for 5w30 synthetic as the preferred oil, with conventional straight 30 weight being allowed for temps above 40°F. At full operating temp in an air cooled engine both oils should be the same viscosity, with the synthetic having the added benefit of lasting longer.

 

[Klutch9]

Considering the 20 oz of oil that was specified for that motor, I'm guessing it's the same B&S engine we have in our walk-behind. That motor has been used for years, and is very good... as are all B&S motors IMO. Ours still runs perfect, and gets new oil once per year. But there were multiple times when it went 2 years on the same oil. Another note: the air filter has never been replaced on our mower. I clean it with compressed air every so often, and give it a few good smacks to knock debris loose. Seems to work well. We also have a larger B&S motor on our riding mower. It has been in service for 12 years now, and has mowed a LOT of grass, since we have always had a pretty big yard. Never changed the air filter on this one either, just cleaned it. Oil sometimes was used for 3 seasons straight. After 10 years, I checked the valve lash in the head... it was absolutely spotless, and still right at factory specs.

Honestly, I think many people neglect lawn mower maintenance, but they still keep on runnin'.

 

[TFB1]

Originally Posted By: Trucku

I filled the engine with 20oz of Mobil 1 5w30, ran the motor for a few minutes and repeated this drain and fill another 8 times before I was happy.



Eight times???

As far as I know the '04 Honda engine I installed on one of my old Snappers had never seen a oil change, was almost black... It belonged to one of my buddies neighbors, he said they never serviced it and usually just let it set in the spot where they finished cutting... The deck had holes in it you could stick you fist in... After I changed it, cut grass four or five times(we're talkin' approx six weeks), then changed it a month or so ago... Still looks as clean on the dipstick as when first changed...

 

[dwendt44]

Smoking could be stuck rings.

Give it a while to clear itself up. A few times mowing a yard then change the oil again.
A 5W-40 might be the best choice.

AutoRX claims it can clean up/free up stuck rings.

Some of the newer small engines run on the aluminum cylinder (no liner). If that's the case with yours, the ratty oil may have scored the cylinder enough to allow oil blow by.
Nothing can be done with that problem other than buy a new engine.

 

[TFB1]

Originally Posted By: dwendt44

Some of the newer small engines run on the aluminum cylinder (no liner).

As far as B&S, unless it's commercial or industrial grade that's almost every single cylinder engine they've produced, if it has iron sleeve will likely be proudly announced on a sticker...