I'm not familiar with the 2GM
, but I had (my brother owns it now) a 3GM
and it lost
most of the oil while just running it in the slip for twenty minutes a few weeks ago. Turns out that there is a small external steel
oil line that goes from the starboard side of the engine around the back and terminates under the starter on the port side. There are four banjo fittings on it and a crack developed near the fitting at the back of the engine. The new replacement line looks like it's now copper or bronze. If the 2GM
has a similar external pressure line I would check it after filling the engine with oil. It was immediately obvious where the oil was leaking when I started the engine. Not easy to replace, two people were necessary unless you have full access to the starboard side of the engine.