Do I have the right pump?

[amuller]

So it is a 1969 Evinrude 25 hp. Not a Big Twin but a souped up FD type.

The blue motor has a green, presumably older, five bolt gearcase on it which I dropped as it didn’t seem to pump. (What year did the green paint end on these?)

Impeller seems fine. Pump housing is 303070, secured with three of what look like #8 by 32 screws. Plate seems to match though bent near the shaft hole. The case is drilled and threaded for four screws. Three little screws seem a rather flimsy attachment?

So I’m trying to figure out if this is an OK pump housing for this application. There are a few different housing numbers and I have no idea what the real differences are.

Any guidance appreciated.

[fleetwin]

Hmmm, I wasn’t aware of any earlier FD type pumps/housings that used 4 screws instead of three…Will have to research this a bit, but I don’t think you can mismatch this stuff and have it pump correctly…
Post some pictures if you can….

[fleetwin]

OK, well marineengine.com only goes back as far as 57, but the same style pump/housing/screws are used from 57 right up to 1978…. I suppose
55-56 models could be different, but I don’t think so…
Is it possible that someone drilled/tapped the extra hole in the case? Doesn’t seem likely because the housing is so darn thin around the pump retaining threads.
Again, post some pictures….

[amuller]

Pics:

[fleetwin]

OK, well that gearcase must be from the 1979 or newer style 25hp gearcase:
http://www.marineengine.com/parts/johns … rcase+-+25
I am not sure if the water tube will fit properly into that new style pump though…You will have to do some investigating with the new/old parts.

[Steve D]

I checked 4 or 5 housings (Edit: gear case housings) and they all had 4 holes despite the pump housing only using 3 of them. By ’69 that housing 303070 superseded to 313543 that had a recess on top that allowed a spacer 313519 to fit in and that isolated the driveshaft. Look up your exhaust housing and see if there is a recess to accept the top of the spacer. (Added) If there is, then no, you don’t have the right pump housing. But that wouldn’t prevent it from pumping.
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[frankr]

Strictly guessing here. This is 1979

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[fleetwin]

OK, so maybe that three hole stuff will fit properly, never really noticed what Steve points out…In any event, the paint on top of the gearcase looks like light blue paint, not green, someone painted that newer style gearcase. So, back to the original question, why won’t it pump? You mention the SS impeller plate is slightly bent, that could be enough to mess things up. I would clean things up more, get all the crud out of the impeller housing holes, seal a new SS impeller plate to the housing, and replace the impeller…How is the condition inside the impeller housing, excessive grooves/corrosion? Don’t forget to make sure the tiny bleed hole is clear in the impeller housing as well…
And yes, I agree, using just three screws is pretty poor…Making it all the more important that the mating surfaces are clean/flat, or else the pump will just pull air…
Just looked at Frank’s 79 diagram…I guess the holes must line up seeing that the water pump was in place, but I don’t know if the screw pattern/sealing pattern changed from 78 to 79, so hard to tell if you have the 79 style gearcase. The part numbers do not supercede from 78-79 though. Looks like the 79 set up has a pinion needle and thrust bearing which the 78 models did not, the 79 also has the plastic water pump housing…
I guess the question is has this engine ever pumped water OK for you, or did you just buy it and it doesn’t pump. Needless to say, if it pumped OK in the past with this set up, it should be able to work now…

[amuller]

(This post disappeared again. Fortunately I’ve taken to coplying everything to an email in case I have to post it again.)

OK! I was looking backwards, assuming the foot was older than the head. Somebody used the old pump parts on a newer case. Couple questions:
Can anybody tell me what the specs are of those 4 mounting screws? #8? #10? Threads?

marineengine lists a "chrome pump kit" for only $25. Anybody know what’s in it? From the pics I found in doesn’t seem to include the housing? Then there is a "water pump repair kit" for $68 that seems to have everything. I might be able to just buy the stainless plate ($3) and modify the pump housing I have, which is in OK shape, and get screws at the hardware store……

Also, what this "heavy duty gear and clutch dog kit" Does this mean the standard internals are weak?

You all are an incredible resource. Thanks again.

[amuller]

quote fleetwin:

OK, so maybe that three hole stuff will fit properly, never really noticed what Steve points out…In any event, the paint on top of the gearcase looks like light blue paint, not green, someone painted that newer style gearcase.

It looks green to me, but Carol says I’m not good with colors.

So, back to the original question, why won’t it pump? You mention the SS impeller plate is slightly bent, that could be enough to mess things up. I would clean things up more, get all the crud out of the impeller housing holes, seal a new SS impeller plate to the housing, and replace the impeller…How is the condition inside the impeller housing, excessive grooves/corrosion? Don’t forget to make sure the tiny bleed hole is clear in the impeller housing as well…

Impeller housing is OK.

And yes, I agree, using just three screws is pretty poor…Making it all the more important that the mating surfaces are clean/flat, or else the pump will just pull air…

Seems the setup was used on a lot of motors, poor as it looks to us.

Just looked at Frank’s 79 diagram…I guess the holes must line up seeing that the water pump was in place, but I don’t know if the screw pattern/sealing pattern changed from 78 to 79, so hard to tell if you have the 79 style gearcase. The part numbers do not supercede from 78-79 though. Looks like the 79 set up has a pinion needle and thrust bearing which the 78 models did not, the 79 also has the plastic water pump housing…
I guess the question is has this engine ever pumped water OK for you, or did you just buy it and it doesn’t pump. Needless to say, if it pumped OK in the past with this set up, it should be able to work now…

I bought it if $60 with no real expectations. Ran it briefly in a barrel and it didn’t seem to pump. Don’t know if it ever did.

The isolator mentioned was present when I looked, but has been crudely shortened.

So I need to pin down 78 or 79 before ordering anything?

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