Re: Flush motor
Your intakes are on the side of the gearcase right behind the prop aren't they?
I have good luck with the plain black circular muffs mounted on black painted steel rod. I just make sure that the hose hole is directly over the inlet and that it is tight enough not to slip. Sure, some water sprays out around the muffs, but remember, you don't need enough water to cool the engine at 5000 rpm. You only need enough to cool at idle and flush out the salt.
Sometimes it does take a bit of time to prime, but as long as water eventually (reasonable time period) comes out the idle relief vents in the back, you are ok.
I think sombody makes a flusher with square muffs for this application but I haven't needed them yet.