I don't want or expect to fix it. What I'd like is just to run it, in its broken condition, until it quits running. I don't want to annoy the neighbors with smoke while I do it, though.

I suspect that it will keep running for at least a year or two, as long as I don't care that it's smoking.

I might have to check scrapyards. I'm looking at Craigslist for similar mowers with broken transmissions, missing mower decks, etc.

I took a tech class in high school where we rebuilt small engines; that teacher was always happy to be supplied with problems for his students to fix. He doesn't teach there anymore, but if they still have the class then they would probably do it. That's been a backup plan the whole time.

That sounds almost like it could work. :D

AFAIK, chainsaw bar oil is SAE 20 with a few different additives.

Oil Cocktail
 

Those Briggs and Strattons are pretty stout, I had a 66 mower running till the 80's. They lubricate by splash oiling in the crank, course if you get snow, then you get condensation that sits in the cylinder wall and rusts out the bore. So the mix I like is 40% 20/50 synthetic, then 40% good old fashioned 30 weight, its thick, and finally 10% STP. Those Briggs engines can take some pretty thick oil, if that doesn't fix it keep upping the dosage, meaning 60 to 80% 30 weight and if you can find it, 40 weight. What were doing here is making a plug, just going thicker until nothing can get by the rings. And yes, back in high school a friend of mine ran 90 weight in their Dodge Polara, hey it ran.

Now as far as directing your locomotive exhaust, see if you can run the exhaust into the blade area. That way it will be defused into the clipped grass and give the lawn a nice breath of Co2, rather than putting it in the air, put it in the lawn, plants like that stuff.

Come to think of it, in the 90's, I replaced the Briggs with a 2 stroke lawnmower that blew its exhaust right into the blades. It made the 2 stroke pretty quiet and hid the 2 stroke smoke by blowing it into the lawn.

When I use to work on the tug boats, to catch blow by from the diesels, we used to take a 5 gallon oil can and fill it with belts of steel wool and run the crank case vents into the can. Finding steel wool, the best places we found were K-Mart and wood finishing shops, maybe Home Depot.

Great ideas, Scott. I probably will only mow once or twice more this year, but in the Spring I may just try some of those strategies.

run it till it blows, we have a 6hp B&S pushmower that has the nastiest knock and when its under a load it pours blue smoke but id be damned 7 years and still kickin, dont ever winterize any of our mowers either, all fire up in the spring with 4 pulls...(3 of em sit outsde under our boat and reguarly get rain and snow on em)

cant do much bout smoke control, if neighbors complain tell em to shell out the money for a new engine.

have u tried runnin some seafoam in the crankcase? thru the carb?

I disassembled, fully cleaned, and partially refurbished the carb.

I haven't used seafoam, but I did bring it to a shop where they did $50 worth of tests (more than I agreed to :() and determined that it's not minor.

I live in a nice area with clean air, and that's probably as important to the neighbors as it is to me. Also, I have a good relationship with some of my neighbors and would rather not abuse it.

personally being one who fixes other peoples mowers, i do not trust shops alot of the time. ive been "given" mowers that dont run or whatever i take about an hour to fix and its good as new, these are mowers that have been taken to shops and supposedly "looked over" and irreparable without major costs. a new 11hp engine is like 5-600 bucks.

seafoam in the crankcase can free up carbon gunk, ever try any of those "engine restorer in a can" type of things? could be stuck rings/broken rings

yea like others suggest if nothing works put thicker oil in it.

im guessing youve changed the oil, had one mower that would smoke, changed the oil and it immediately stopped...boggles my mind..

I changed the oil about a million times. I think the cause of whatever damage it has now was when the carburetor was overflowing into the engine while turned off, gas was washing down the cylinder wall and into the oil.

I really don't want to keep throwing good money after bad with this thing.

I just emailed someone who listed a free 14hp lawn tractor on Craigslist with no rear wheels and a dead transmission...maybe I can get a decent engine for a couple hours' worth of road trip.

yea thats the best way to get a "new" engine. or sometimes junkyards have well junk mowers.

the worst thing to do is choke yourself out while mowing the lawn

What about a plain-old push (no motor) mower? That's pretty much all I've ever used (had a nice King O'Lawn, but someone stole it). Actually, nowadays, I use my electric string trimmer.