D200 Governor oil leak

[BMW1 42]

We added dye to the oil on a D200 to find an oil leak and discovered the leak seem to be coming from the bottom of the governor.  We recently purchased this tractor so I do not know the history of it.

After removing the governor we found what looks like a casting flaw.  Not sure what else it could be. 

One picture shows the dye and the other the casting flaw?

 

Any ideas what it is and best way to fix?

 

 

[gwest_ca-(File Mod) 11,018]

Not familiar with this engine but normally the crankcase should be under a vacuum when running. When the piston goes down it pushes the air out the crankcase breather. When the pison goes back up the check valve in the breather closes and this should put the crankcase under vacuum provided it is sealed up. The oil fill cap is one common source of a vacuum leak. There is as much air moving below the piston as there is above the piston so the volume of exhaust gives you an idea of how much air movement is involved. A hairline crack should not be much of a leak provided everything else is sealed. Worn piston rings will reduce the vacuum or eliminate it and is called blowby. If real bad when the fuel is ignited it can pressurize the crankcase.

If the leak is from a pressurized oil supply then that is a problem.

Just a thought.

 

Garry