Poulan 245A Unusual Air Leak?

[JonCraig]

Craigslist find Poulan 245A. "Newer" style with solid state ignition, in case that helps. Piston is scored so I'm doing pressure/vac tests to figure out what all seals I need to buy (but assuming all of them, of course).

I hook up my air line, and hear a large leak. I discover that it's NOT coming from either of the crank seals, nor the cylinder gasket, but from one of the holes that mounts the oiler cover. I put my finger over it, and can hear & feel the pressure building up.

So my question is... has anyone ever seen this before? What on earth connects that screw hole to crankcase pressure?

I've attached a picture of me pointing to the hole in question, as well as some screenshots of the IPL. Note that the hole in question is where (in the 2nd IPL screenshot) screw # 46 goes into. All it does is hold the oiler cover on. I find it hard to believe that Poulan would have designed crankcase pressure to go thru that passage for some reason.

Thank you in advance for your help. This one has me stumped!

--JC

 

[hotshot]

Classic saws, that one & the 306s.

That's simply a threaded through hole into the crankcase, plug those two up before P&V testing the seals. 2 short bolts & neoprene or viton washers will seal them up.
When you reassemble, use Motoseal on those two bolts too, just like you found them.

It is not unusual for the case halves o-ring to be leaking badly, the original ones were made of some type of plastic & thus cracked apart, producing leaks.

The later ones were true neoprene o-rings, pn 530019004.

This pic shows a factory cast void that produced a leak at that joint....JB weld filled it.

.