Exmark 708 engine crankcase pressure

[Savage]

Just for general knowledge......
708cc Exmark engine:
How does the crankcase maintain pressure with the drain hose running up the side of the engine connected to the engine cover?
Does the drain hose act as a crankcase vent as well?

Generally, the oil drain is plugged with a bolt.
Thanks

 

[bertsmobile1]

No the drain is a drain pure & simple
Crankcase vacuum is maintained by the breather which plugs into the back of the air filter
The engine end has a reed valve
Occasionally the valve gets crud stuck in it so fails to seal.
This usually causes the engine to become smokey.

 

[Savage]

I haven't taken this engine apart yet.

2019 model, this set-up is new to me.

I was surprised to see they spent the extra two cents installing a hose.