Lawn tractor burns oil, now what?

[gerti]

My 13 year old Craftsman Lawn tractor has started to burn oil, and it is getting worse. I need to top it off for every use.

I like the tractor, it is easy to work on, and spare parts are relatively cheap.

So what do I do: use it until the engine dies, replace the engine, have the engine rebuilt?

Of course I'd like to keep the expenses low, it'd be a shame to spend a lot of money on it only to have the gearbox go next.

The engine is a Briggs & Stratton "I/C Gold 15 HP OHV" with "cast iron cylinder liner". I don't know much about engines nor have the proper tools or time, so wrenching on the engine myself is out.

Is it worth it to have the engine rebuilt? What might that cost?

Thanks for any insights!

[Pappy]

Most likely a cylinder/ring wear problem. I'm sure it could be bored and sleeved but it would probably cost more than a factory rebuilt short block assy.

[crokett]

It cost more for the reboring than a new engine 10 years ago when my dad looked into it for his Gravely. Forgot to add that he opted for new rings. It helped a lot but the Gravely still burns a little oil.

[eezlock]

lawn tractor burns oil

Sounds like the piston rings are worn out and need to be replaced. You might want to check with Northern Tools or another supplier like them in your area
for a replacement engine. These costs are substantial, but not as high as replacing the entire tractor would be. If you really like the tractor....might be the best thing to do...something to think about. eezlock

[RAFlorida]

Here's maybe an option.

Saw it on CL and don't know if there's an match up for your mower to swap engines. Just trying to see what might help you.
http://minneapolis.craigslist.org/grd/775785149.html
Edit. It does look rough, but states engine is good(?) and OBO listed too.

[LCHIEN]

It's pretty clear wahts wrong withthe motor Obviously the thing to do is call a small engine repair shop and ask for a quote on rebuilding the engine. They can probably tell you if they can just replace rings or need to rebore the cyl. and how much each will cost. Then you can make an informed decision of repair or replace.

One question I have is why small gasoline engines have such limited lives...
I understand most 5HP class lawnmower engines are worn out after about 7-8 years of service, which represnets 1-2 hours a week for 8 months, once a week use...
Maybe a total of 480 hours...
MY car engine is easily expected to go 120,000 miles which at an average of 50 MPH represents 2400 hours of use.

Is it the load? cars typically run at low torque (cruising at 50-70 mph). and lawnmowers run pretty much continuously at high torque?
is it that car engines are made of better materials?
is it that car engines run at lower RPMs, maybe averaging 2000 for a 6 cyl vs. (I'm guessing) 3000 for a lawnmower engine?

[docrowan]

One question I have is why small gasoline engines have such limited lives...

Much less technology (metallurgy, design, etc) in the small engine. Most small ones have no oil filter and no oil pump. The dimensions of the bore, rings, and piston are much sloppier - ever notice how quickly the oil turns black? Other than safety features, the design has remained virtually the same for I know 30 years and probably more than that. 30 year old car engines required much more maintenance than today's car engines. My '91 Mirage had to have valve adjustment every 15,000 miles, what new car needs that anymore?

Most are subjected to harsh conditions -very little maintenance, very dusty conditions, etc.

[LCHIEN]

that makes sense. So for maybe doubling the cost of the engine, can they add tighter tolerances, better rings, oil galleries, an oil pump and filter, some electronic ignition and sensors and make an engine that lasts for 20 years, pollutes minimally (I hear IC Lawnmowers emit tremendous pollution for their size) and is always real easy to start? A few AA batteries to provide startup electrical for the CPU and some clever (magneto or Bendix?) could provide what little electricity is required while running without a full alternator and Pb-So2 battery.

If the engine cost doubles and the original engine was 50% of the lawnmower, then the new engine cost is 2/3 of the lawnmower and makes it 1.5 times as expensive as the original version for 3 times the life...

Would be an interesting economic study...

[docrowan]

On the other hand, when I was growing up we had a B&S engine that outlasted the mower deck - maybe 20 years. My dad was not that kind to it, rare oil changes and spark plugs only when it got to hard starting. No point in making the engine last longer than the wheels. Replacement wheels are pretty dang expensive for a piece of plastic with a little steel bearing.

I'm curious about how long my mower engines will last, particularly my riding mower. I'm trying to do everything right, I store it in a shed, installed an hour meter, and have been pretty scrupulous about oil and filter changes. I blow off dust and grass clippings from the whole mower after every use and I degrease the engine every spring to aid in cooling. The only thing I haven't done is wax the mower but if I really get bored one spring I'll even do that. I'd love to have it last until I retire, 25 - 30 years.

[LCHIEN]

On the other hand, when I was growing up we had a B&S engine that outlasted the mower deck - maybe 20 years. My dad was not that kind to it, rare oil changes and spark plugs only when it got to hard starting. No point in making the engine last longer than the wheels. Replacement wheels are pretty dang expensive for a piece of plastic with a little steel bearing.

I'm curious about how long my mower engines will last, particularly my riding mower. I'm trying to do everything right, I store it in a shed, installed an hour meter, and have been pretty scrupulous about oil and filter changes. I blow off dust and grass clippings from the whole mower after every use and I degrease the engine every spring to aid in cooling. The only thing I haven't done is wax the mower but if I really get bored one spring I'll even do that. I'd love to have it last until I retire, 25 - 30 years.

Good luck, Chris. The engine repair guy told me that around here, LM engines last 7-8 years and that's it.

Maybe that's the design, the mower companies want to sell you a new mower every 7 years, their livlihood depends on it. If they lasted 20 years they'd be out of business. Lucky if they sold you 2 lawnmowers in your lifetime.

[ironhat]

Yes, Chris, it is possible to keep it up and running for that long. I don't know if they put more longevity into the larger engines and trannys in the GT (Garden Tractor) series than the Lawn Tractor (LT) series or not. I have a Craftsman GT, 18 HP, standard gearbox that I bought in 1984 that is still going strong. It is now semi-retired because the wife wanted to get away from the gearbox and move up to hydrostatic. Personally, I like the old one better even though the new one keeps the blade RPMs up even when the tractor is slowed which give a better cut. Like I said, I don't know how that factors into the equation so it's probably not worth much. Just keep up the maintenance and you'll be a happier camper.

[Woodshark]

Up to 5 years ago I had a Snapper riding mower that was older than I was. I was born in 1960! It had a old Tecumseh 12HP engine that had no recoil for the starting cord. You had to knot the end of the starting cord, unsert it in a slot, wind the cord around the top and pull. After you pulled the cord was detached from the engine and you had to start again.

The engine always started on the first or second pull. The only reason I got rid of it was because the deck had large holes rusted out and the brakes were shot.

[dick541]

Best bet , get all the apec, off the old motor include the shaft size and length and go to Northern and get a new motor.
dick

[sparkeyjames]

I dunno the old mower I have keeps clipping along (pun intended). I have a 1978 Montgomery Wards lawn tractor 11hp. This mower cut my father large yard for quite a few years. Then he decided to use a mulching push mower and let the tractor sit from about 1993 to 2006 when I bought my house. We got her running and it now does a great job whacking grass on my 3 lot property. It has a Briggs and Straton engine on it. I change the oil every spring and it does not burn any either. I expect the tractor frame and everything else will fail before that motor does.

[gsmittle]

**WARNING** Not a serious answer

You could put it on CL as a diesel-engine mower...

g.