Intermittent oil burning on a 31P777

[finfin]

I had been mowing my ditch bank for 15 minutes or so when my mower started blowing gobs of thick white/blue smoke. I was mowing with the low side of the bank to my left. I disengaged the mower, throttled back, and shut the mower down. After about 4 minutes I thought I would try to start the mower and get it back to the house. Started right up and no smoke. I mowed another 15 or twenty minutes without incident.
The air filter was not oily. The oil is full maybe a little bit to full, but nothing to dramatic. I have never had this occur before. It didn't sound like a belt. I really thought it was oil.
Any thoughts? Maybe a crank case vent valve stuck open?

 

[ILENGINE]

may have been picking up extra oil from running on an angle with the breather toward the downhill side. Extra oil may have increased the likelihood.

 

[KrashnKraka]

may have been picking up extra oil from running on an angle with the breather toward the downhill side. Extra oil may have increased the likelihood.

Confirmed.
Slope mowing requires a lower than "full" more than "low" level or pickup occurs.

KK

 

[finfin]

Confirmed.
Slope mowing requires a lower than "full" more than "low" level or pickup occurs.

KK

Will do! I was thinking the same way about "lower than full more than low. Has to be something like that to have gotten better on it's own.

I need to change the oil anyway... Should I use a straight 30W or multi viscosity?

 

[KrashnKraka]

Will do! I was thinking the same way about "lower than full more than low. Has to be something like that to have gotten better on it's own.

I need to change the oil anyway... Should I use a straight 30W or multi viscosity?

maaaaate...I am wimping out on that question, waaay too much differing opinion on
the topic.
Bottom line?
Go with the engine manual spec and common sense when considering your usage type.
Should you get a problem...?...wave the manual at 'em.
IME machines mission critical come with a service instruction fixed to the
machine/engine/motor. Mowers appear to be exempt from that industry norm.

Back on topic? You may also find that at speed (running along, no mow) in
lumpy country the engine may still pickup occasionly. Slow down, this feature
of these engines could not be a good thing long term.

Trust that helps some.

KK

 

[DJ660]

Head gasket blown between cylinder and pushrod chamber. Running it on sidehill (Carb up) combustion chamber is pulling in oil that returning to crankcase. Do a leakdown test. Briggs OHV's model 28,31 and 33's this is quite common. And whoever replaces the gasket make sure the HEAD IS RESURFACED. Not uncommon to see heads .008-.012 warped in area gasket is blown out.

 

[KrashnKraka]

Head gasket blown between cylinder and pushrod chamber. Running it on sidehill (Carb up) combustion chamber is pulling in oil that returning to crankcase. Do a leakdown test. Briggs OHV's model 28,31 and 33's this is quite common. And whoever replaces the gasket make sure the HEAD IS RESURFACED. Not uncommon to see heads .008-.012 warped in area gasket is blown out.

Quite possible, pumping oil - even droplets - is never a good thing.
The OP should have noticed an accompanying (immediate) performance loss tho', hey?

KK

 

[DJ660]

Power loss.......... If it has been gradually losing compression over a few cuts, he my not even notice it.

 

[Tinkerer200]

"Oil maybe a little over full"?

Gas in oil?

Walt Conner