I have a 1991 OMC Cobra with a 4.3L in a SunBird Corsair 198 that's been quite the project. After rebuilding the engine and re-installing, it doesn't seem to be pumping water running off the muffs in the driveway. Barely any water, mostly steam comes out of the exaust bellows or prop. This is at an idle, too. 
Testing with the engine off, I leave the hose on full blast, and pull the impeller pump housing off, the water won't even come up through the pump inlet holes unless I manually clamp the muffs to stop the leaks around them. When I do this the small drain holes in either side of the drive are shooting out about 3' streams of water, while a small dribble comes up through the pump inlet. Sounds to me like a blockage or leak in the lower unit. What say you?
I tried to pull the lower unit to inspect it while the outdrive was still attached, but it doesn't want to come apart. Is it necessary to pull the whole outdrive before removing the lower unit?
Any comments would be appreciated.
Testing with the engine off, I leave the hose on full blast, and pull the impeller pump housing off, the water won't even come up through the pump inlet holes unless I manually clamp the muffs to stop the leaks around them. When I do this the small drain holes in either side of the drive are shooting out about 3' streams of water, while a small dribble comes up through the pump inlet. Sounds to me like a blockage or leak in the lower unit. What say you?I tried to pull the lower unit to inspect it while the outdrive was still attached, but it doesn't want to come apart. Is it necessary to pull the whole outdrive before removing the lower unit?
Any comments would be appreciated.