Well, The test started out well…..but then…

[gjonz]

Yup. Pretty normal for that type of situation. That is why I shave a few thousands or more off the bottom of that bearing on the pump. Just enough to allow the shock to expand without destroying the housing.

It was asked a few posts back about why these springs crack. My best guess is age, and brittle hardened metal that is frankly over-sized for the job.

Greg

[drifter]

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.

[fleetwin]

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.

[drifter]

I too cannot make a correlation to the shock expanding and the pump failing. As for the l/u being deep enough, the water level is well above the pump housing in a tank I have used for 20+ years. Tank depth is 20″. The impeller housing looks fine (smooth and no obvious wear pattern). I removed the rubber water tube grommet and made sure the relief hole was clear. The stainless plate does have a wear pattern at the hub, but is perfectly smooth at the vane end. The L/U was thoroughly cleaned and inspected for water flow. The intake plate (with holes) was replaced by one with scoops). The impeller, though not OEM, was new and is a brand I have used before. Grandma always said: “New don’t mean good”. So, if there is a suspect, that might be it.

[bobw]

The wear pattern at the hub area of the impeller plate seems to confirm the hub area of the bushing plate was pushed upward by the spring failure and the plate is now somewhat warped. On another note, that small volume of water in that small tub will likely get hot pretty quickly from the engine exhaust and lead to overheating the motor. Great looking motor!

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

• This reply was modified 4 years ago by bobw.

[fleetwin]

That impeller housing and plate are worn, water is probably escaping up and out of the center of the impeller housing. I don’t see evidence that the seal housing is bent upwards and contacting the SS housing, I think the wear is probably from years of use. I’m not a fan of the Sierra impellers, but everyone has their own experiences. In this case, I don’t think it is the fault of the impeller, it is just unable to seal with the grooved SS plate and impeller housing….

[Author]

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