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Rick
Rick, Factory Authorized Trainer
Category: Small Engine
Satisfied Customers: 8057
Experience:  Outdoor Power Equipment technical trainer since 1990, covering eight states.
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Riding 1994 MTD lawn mower - 14 hp I/C Quiet Briggs & Stratton

Resolved Question:

Riding 1994 MTD lawn mower - 14 hp I/C Quiet Briggs & Stratton Engine - model 287707 Type 0220 01 Code(NNN) NNN-NNNN.

Engine started burning a lot of oil - engine is well maintained - trouble shooting book suggests that the engine breather may be defective or dip strick seal may need replacing - requested data from the briggs site. Can nt come up with the model above or any data. I can not order parts or troble shoot if I can not come up the proper info, or the location of engine breather.

Jim Haines [email protected]
Submitted: 7 years ago.
Category: Small Engine
Expert:  Rick replied 7 years ago.

Hi Jim,

 

Let's start with a parts breakdown for you:

 

Parts List

 

How much oil is it using?

 

 

 

Customer: replied 7 years ago.
when the engine is at idle and you increase the engine speed the engine will stumble and produce oil smoke then level out. It will also smoke while under load.
The engine will burn apprximately 250 ml in a 2 hour run.

Expert:  Rick replied 7 years ago.

What color smoke? Does the oil in the sump smell like gas?

 

Customer: replied 7 years ago.
grey black
Expert:  Rick replied 7 years ago.

Dark smoke is unburned fuel. Oil will be bluish white. Does the oil in the sump smell like gas?

 

Customer: replied 7 years ago.
Went out to the shed and checked the oil sump. Mind you your talking to a person in Northern Canada where winter has started.

The oil is unusally dark in colour, pretty well black and more fluid in tecture. Smells like dirty oil not fuel. Normally the oil after a summer season of operating is reasonably clean and I would service the unit in the spring prior to operating.
Prior to storing the unit for winter I noticed oil dripping from the area of the carb. But this only occurred on two occassions after cutting the grass.
Expert:  Rick replied 7 years ago.

By more fluid in texture, do you mean the oil seems thinner? Does the oil level appear to be increased? What does the spark plug look like



Edited by Rick on 11/5/2009 at 10:07 PM EST
Customer: replied 7 years ago.
Yes the oil appears to be thinner. The oil level decreased approx. 250 ml after about two hours of use.
Expert:  Rick replied 7 years ago.

From your description, I believe you have more than one problem here. The thinning of the oil is most likely that you have a bad needle and seat in the carburetor. When the unit sits, fuel will flow through the carburetor and then into the cylinder, past the rings and into the sump, mixing with the oil. This often will cause the oil to pumped up through the breather into the carburetor through the breather. Check the float by shaking it. If there's any fuel in the float, replace it as well as the needle and seat.

 

I also suspect a blown head gasket between the cylinder and the push rod tubes. Either that or worn rings. The dirtiness of the oil tells me you're getting exhaust blowby down into the sump. Head gasket is the most likely (and least expensive). I think you'll need to remove the head and take a look. Be sure to check the intake valve stem seal while you're at it.

 

Considering you've got a 15 year old engine, that's not bad. You must have taken really good care of it. Most don't make it half as long.

 

I hope this is helpful!

 

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