Re: 1965 Ski-Twin Mod 3552B questions

[Don]

quote amuller:

quote FrankR:

Back in those days, boats were made of wood and had keels. Therefor the motors were designed to run deeper. A straightedge extending the boat bottom out should fall somewhere between the water pump bulge and the cavitation (AV) plate.

Makes sense.

The top of the AV plate is a full five inches below the centerline of the pump bulge. So, if the motor was shimmed up to align the plate with the bottom of the transom, or the motor was used on a 20 inch transom, seems that the pump would be starting dry sometimes and might not pick up it’s prime. (Though I know there have been successful motors with the pump high in the leg.)

In truth I only got this motor for the internal gearcase parts, but nobody seems to have much bad to say about them.

Well, I think I understand what you are concerned about, but it might be best to post pictures…
In any event, it is normal for the water pump bulge to be up and out of the water while the boat is planing. The water is actually being forced into the pump by high water pressure against the pick up screen on the exhaust snout behind the prop. So, losing pump prime is not likely….