TOPIC: lower unit water intake? & trim tab...

lower unit water intake? plus is there a trim tab on these Mark78' dock busters? nothing like my 650 it seems. Tried looking on line but cant find a good drawing.....

Bill, I don't have a real good pic of it, but the MK75 and MK78 don't have a "trim tab" per se, they have the exhaust "snout" that acts like a trim tab. Of course, non-adjustable.

www.marineengine.com/parts/mercury-mark-outboard-parts/mark-75a-78-78a/all/gear-housing-assembly-complete

The old D/R lower units intake water from the underside of the anti-ventilation plate, same as the non-flow-thru-hub 4-cylinders do. There should be a stainless louvered screen over the hole. On the inside, a short run of copper water tube goes to the intake side of the water pump, sealed at both ends by a rubber grommet.

See the attached pic which has a decent view of pump side of the gearcase.

Flow-Thru Exhaust D/R models 700 and 800 have a removable, non-adjustable trim tab/water intake.

Hope that helps...........ed

I get it, tx
the outlet points slightly to port. but that inlet is really small? they had this motor blocked up with a piece of one inch wood. if known how high can the cav plate be above the hull bottom and not starve pump for water?...