MasterMech , maybe you can tell me what I'm seeing here? This afternoon I decided to figure out what was wrong with a pre-x-torq 372 that has been sitting on my shelf for a while. This is the first 372 I've ever worked on, but I expected it to be fairly straightforward. I went to do pressure and vac tests, and got a bit of a surprise. There's a small hole in the side of the crankshaft, right in the middle of the area where the clutch bearing sits, and when I attempt to pressurize the crankcase, air leaks out of that hole. It seems so improbable that there would be a passage from there into the mixing area, but I can't see any other explanation. Even weirder, it behaves as if there's a check valve in the passage; leakage only happens when using pressure. Under vacuum, it holds just fine. Can someone tell me what might be going on here? My best idea so far is that it's an automatic oiler for the clutch bearing, and that doesn't seem like a very good idea at all.
That is a oil hole for the clutch bearing and is perfectly normal. I have a Husqvarna cutoff saw that I rebuilt and it has the same hole in the crankshaft. The hole does go into the crankcase and is suppose to allow fuel oil mix to the bearing for the clutch. My saw runs perfectly fine. If you want to pressure test the seals then just plug the hole.
Thanks, Mag Craft . Wonders never cease! Now I'm going to wonder how they managed the machining. Seems like a lot of trouble to go to, just to oil the clutch bearing.
