Reply To: Well, The test started out well…..but then…

[Don]

drifter wrote:

Yes Tubbs. That is the crack.

I have a Sea King owners/operators manual for a 1956 (5hp). In the manual it states to remove the intake plate when running in a tank.

Do you recommend doing this?

I guess I’m still concerned about the water flow coming and going when this motor’s shock let go. It was pumping well and when the problem occurred it stopped pumping.

Drifter
Well, that kind of looks like a casting flaw/mark, not much of a crack in any event. So, I don’t think that crack was the cause for the engine to stop pumping….
Forgive me if I have forgotten details so will start from the beginning…
How deep in the tank were you running the engine? The water level needs to be over the gearcase/exhaust housing joint in order to pump OK in the test tank. Like Frank says, these pumps are not real good at moving air. Was the engine in forward gear or neutral when it seemed to stop pumping?
One thing I have noticed about these pumps over the years is that they will seem to stop pumping if run in neutral or reverse excessively while in the test tank, which is usually a good indication that the water pump needs to be serviced. Is the impeller housing in good shape? How about the SS impeller plate? Had you replaced the impeller with a new OEM piece? I’m not sure why the manual prescribes removing that intake plate, but it can’t hurt to remove it and have a look in the cavity…Oftentimes the little holes in the plate get plugged with tank debris, perhaps there is some crud behind the plate in the cavity. Later model intake plates had little scoops to help direct/force water into the cavity. Post some pictures of your impeller housing and plate….
I guess what I am saying is that I think the sprung shock and weak pumping are independent conditions not related to each other.