Don't know about Mercruiser stating anything, they only mention muffs in their user manuals (I looked), nothing in service manuals and they deleted sterndrive flushing video off their website. I smoked my first impeller running things in a water trough. Maybe should change to an oil thread to...
I don’t know how high you need to be, but Alpha pumps are vented to self prime when submerged. they don’t lift worth a damn. I don’t have thirty years working on em though, so happy to accept contrary opinions.
Would add that you pretty much can’t test shifting beyond what you do on muff without loading the prop in the water. Most of the shift system is designed to accommodate always being under a load. Shifting out of gear is the difficult part when the entire drive train is always loaded.
One of the tricks is to loosen the mount adjusting bolts until on both sides, with the motor suspended from the front lifting bracket - that bracket is there just for this purpose. Then adjust both sides until they have equal pressure. Last time I did this was able to suspend the motor off a 2 x...
Don't know if being IN the lake will change the dribbling or not, but the back pressure on the exhaust from pushing it out a foot under water does change your mixture as exhaust evacuation is under pressure.
Be some work and significant added expense. If you like doing fiberglass fab work the extension on the motor mounts is easy enough. Will be interesting prop'ing the 1.84 4.3L drive to a 5.7L motor.
Gimbal bearing carrier rings have notches cut into them that allow the bearing to be rotated and removed from the carrier. Is that by chance what you are referring to?
