Cub Cadet MTD P71 Series - Manual (Page 63)

Lubrication
57
Lubrication system
MTD uses a splash lube system for it’s vertical shaft
engines. The oil slinger gear has paddles on it that
“splashes” oil around the inside of the engine. See Figure
5.4.
The splashing action will also atomize or change the oil
into a mist. There are two oil passages that run along the
engine cylinder. The one just above the oil line is the oil
supply passage. The oil mist will flow through this passage
to the cylinder head. The supply passage lines up with the
top crank arm so that some of the oil on the crank arm will
be flung into the supply passage, forcing additional oil up
to the cylinder head. See Figure 5.5.
The second oil passage is located between the tappets.
This is the oil return passage. As the name implies, it
allows the oil collecting in the cylinder head to return to the
sump. See Figure 5.6.
NOTE: Because these engines use splash lubrication, the
type of oil and the oil level is critical for proper
operation of the engine. If the oil level is too low,
the paddles on the governor gear can not splash
the oil into the engine. If the oil level is too high, the
oil will not change into a mist to reach the upper
side of the engine.
Figure 5.4
Paddles
Slinger gear
Figure 5.5
Figure 5.6
Oil return port
Supply passage