28 CID Briggs

[mr-moe]

I've got this older MTD mower with a 281707-0137 engine in it.
Sat for two years not running.
Drained fuel system.
Removed carb. and cleaned out.
Runs good at idle, when I bring up full speed it starts to pump engine
oil into the carb. load up and quit in a cloud of oily smoke.

Restart at idle, get running at idle to clear oil from cylinder.
When it's running at idle it runs good.
if I crack open the dip stick it will quit running.
Ideas?

[38racing]

Maybe the breather is defective. As a test remove breather hose from carb and I assume you will see oil pumped out of it. I'm assuming oil level is correct with no gas in it. Capacity is 1.4 litres. Engine stopping when dipstick removed is a new one to me. Usually it just means oil sprayed around.

[KE4AVB]

Also can be a bad exhaust valve guide or overfilled on oil.

[mr-moe]

I'll check out.
Thanks for the ideas

[bluemower]

The 281707 was described in the 1987 Briggs update. This engine had a cast iron sleeve and improvements to the cooling fins and exhaust valve. The IPL indicates some of these may have been equipped with a pulse fuel pump. I believe this was no longer manufactured in 1991 when the 286700 engine was offered.

An engine this old most likely has internal wear and combustion pressures are reaching the crankcase. You did not mention the oil. The wrong grade of oil or oil contaminated with fuel is likely on older equipment and diluted oil will easily pass through the breather. Consider draining the oil and servicing with SAE 30. A crankcase vacuum check may provide clues.

[38racing]

I just inherited a Murray rider with that engine. Been cutting with it. No oil consumption. Now conditionally sold. I have a couple 282707 as well.

[mr-moe]

Follow up.


Drain holes in crankcase breather were plugged up with gunk, not allowing
oil to drain fast enough.
Thanks for all the great responses
.

[RoyM]

Thank you for letting us know. Lack of maintenance is so often the problem.