Mercruiser alpha one gen 2, 4.3l. 1992

[JHinMT]

Pulled motor to access y-pipe holed by flapper pin. Boat is a 19' welded and riveted aluminum v hull fish / ski open bow boat. The front engine mounts are a mess. They are a welded aluminum box backed up with plywood. One has slightly buckled, the aluminum surface the front mounts rest on are deformed - punched down. The engine itself was shimmed with 1/4" plywood over the carpet.

I plan to rework the mounts a bit. Basically I'm going to laminate a 6" x 12" x 1/4" aluminum plate over each mount box (matches the wood shims so this shouldn't change final mount height). I'm going to bed the plate in marine epoxy (pc11 maybe if I can source any locally). I put a machinists level on the transom mounts and adjusted the trailer to get the transom mount points as level as I can get them. When I bed the plates I'll level them so they are parallel to but offset from transom mounts. I think that gives me side to side baseline.

What about front to back? Are the transom mount axis parallel to the boats transom or is there a built in angle of the transom assy? I could set my plates parallel to the floor, but I dont know the floor is square to the transom mount axis.

Sorry if this is unclear.

 

[solar7647]

In my experience, level to the floor. The front mount bolts are used to lift or lower the front end to get the engines aligned. If they are too low you won't have the travel in those bolts to raise it high enough, if they are too high you will bottom out before the engine is aligned.

Every one's I have seen seem to be level to the deck of the boat.

 

[JHinMT]

Thank you. I have more room to lower the front of the engine than I do to raise it, but I do have 3/4" or so it could be raised.

I've been messing with raising and lower things and checking level. As near as I can tell with the transom mounts vertical, the original front mounts are level (and not parallel to the floor.)