My Lawnmower Forum banner

Blue Smoke From Exhaust

8883 Views 6 Replies 3 Participants Last post by  Mark / Ohio
My lawn tractor is throwing a LOT of blue smoke from the exhaust. Where do I need to look to figure out where the oil is coming from?
Craftsman 917.274822
1 - 7 of 7 Posts
I would definitely check the oil level first off. Maybe a stuck float allowed gas to drain into the crankcase. Next, take a look at the crankcase ventilation to see if there is an obstruction allowing the oil to be drawn into the carb.

Maybe some others will have more thoughts.
There's also oil "dripping" onto the fuel filter but from WHERE!! And I can also see oil coming from below the fuel filter on the actual engine itself.....
I would definitely check the oil level first off. Maybe a stuck float allowed gas to drain into the crankcase. Next, take a look at the crankcase ventilation to see if there is an obstruction allowing the oil to be drawn into the carb.

Maybe some others will have more thoughts.
The problem with your reply is I don't know where the "float" is or how to check crankcase ventilation..... Maybe a little more info or perhaps a link (that I've searched and searched Google for) of a diagram showing these things and what to look for. Thanks though!
BTW, the B&S website was USELESS!!!
The problem with your reply is I don't know where the "float" is or how to check crankcase ventilation.......
First place I would look is inside the box that holds your air filter. Maybe that is where the oil is dripping from and also getting into the combustion chamber creating the smoke out the exhaust. (The crankcase vents via a check valve of sorts into the intake manifold via a small tube running from the valve cover.)

I'm having trouble getting your model number to show up in Sears Parts Direct. Do you have any Briggs numbers? Hp, age, any idea how many hours is on the engine? Overhead valves?
First place I would look is inside the box that holds your air filter. Maybe that is where the oil is dripping from and also getting into the combustion chamber creating the smoke out the exhaust. (The crankcase vents via a check valve of sorts into the intake manifold via a small tube running from the valve cover.)

I'm having trouble getting your model number to show up in Sears Parts Direct. Do you have any Briggs numbers? Hp, age, any idea how many hours is on the engine? Overhead valves?
Hi. The B&S model # is 31p7770296e1 It's an 18.5 HP OHV Intek Plus from about 2004/2005/2006 or so Craftsman Mower Model #917.274822. The first 2 years I had it I mowed the lawn AND plowed the driveway. The last couple years I've just mowed the lawn. So, as far as hours on the engine I'd figure...... alot but not tons. It doesn't have an hours guage on it.
Hi. The B&S model # is 31p7770296e1 It's an 18.5 HP OHV Intek Plus from about 2004/2005/2006 or so Craftsman Mower Model #917.274822.
Unfortunately Sears parts Direct is only showing a 917274821 & 917274820.

But I did get the engine number to show up:

http://www.searspartsdirect.com/par...03500?pathTaken=&prst=0&shdMod=31P777-0296-E1

The first 2 years I had it I mowed the lawn AND plowed the driveway. The last couple years I've just mowed the lawn. So, as far as hours on the engine I'd figure...... a lot but not tons. It doesn't have an hours gauge on it.
Using your engine number I found this:

Small Engines (Lawn Mowers, etc.): B&S 31P777 0296-E1, blown head gasket, twin cylinder engines

and this:

Small Engines (Lawn Mowers, etc.): B&S 31P777-0296-E1, automatic compression release, blown head gasket
See less See more
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top