25hr Inspection of 912is - concerns

[Dave S]

Dan,

On the 912, a differential compression test will not introduce air into the oil system.

Two things may result in air introduction to the lubrication system:

1) Turning the propeller backwords

2) Opening up the oil system anywhere.

[3kdscf]

Thanks Dave!

One further question, does removing and inspecting the magnetic plug count as opening up the oil system? That has always been unclear to me.

[Dave S]

Dan,

Removing the magnetic plug does not constitute opening up the oil system.

The plug is located to protrude inside the crankcase pocket right by the reduction gear. Sometimes a little oil will run out when removing the plug since oil pools in the bottom of the gearcase. The plug is pretty much in the splatter zone of the large gear.

Dave

[3kdscf]

Thanks Dave!

I will stop wearing myself out trying to spin the prop at 80rpm to purge every time I do an oil change