Do I have the right pump?

[Steve D]

quote amuller:

But based on all said I’m thinking that we have a 1969 leg, with a 1979 or later gearcase. (That based on the four screw holes, the shortened spacer/isolator, etc.) Whoever assembled it used a 3 screw metal pump housing that did not really match the gearcase or the spacer. (But I don’t seen any reason it wouldn’t pump if carefully assembled.) What am I missing here?

My personal opinion, which is only worth about 2 cents, is you have exactly what you’re supposed to have…a ’69 motor with correct everything except the impeller housing and full length missing spacer, which somebody before you Mickey-Moused to fit the wrong impeller housing. And if you notice the updated impeller housing that accepts the spacer also has only 3 holes. That’s just the way they were made. The gear case housings I mentioned earlier that had 4 holes were all pre-’69 and they all take the 3 hole impeller housings, so it’s not like it’s a ’78 or ’79 characteristic.

If you get the correct impeller housing and spacer as suggested you’ll be all set.

[fleetwin]

quote amuller:

Yes, there are unknowns here. But based on all said I’m thinking that we have a 1969 leg, with a 1979 or later gearcase. (That based on the four screw holes, the shortened spacer/isolator, etc.) Whoever assembled it used a 3 screw metal pump housing that did not really match the gearcase or the spacer. (But I don’t seen any reason it wouldn’t pump if carefully assembled.)

So it is a matter of using the plastic pump that matches that gearcase, not of trying to use a newer pump on an older gearcase.

What are the differences in impeller key? The one that came out was plain round pin, not the type squared on one end.

What am I missing here?

There is an old-line OMC dealer 20 minutes down the road; maybe I’ll go and see if they are up for a consult.

Again, I’m sorry I brought this up, and now feel I have sent you off in the wrong direction….I do not think you have a 79 gearcase, and again, the 79 water pump parts will not work on an older gearcase….
The difference in the driveshafts is the impeller key….Your current set up has a hole in the driveshaft to receive the round pin that secures the impeller. The 79 set up has a flat spot on the driveshaft that receives a roller key for the newer style impeller…
I agree with Steve.
But, thankyou for bringing up these questions, I have learned some valuable lessons!

[amuller]

Realized I’ve been really boneheaded about something. The number plate I’ve used to ID the motor is on the bracket, which is white, not on the powerhead, which is blue. So I really don’t know the year or model or power of this motor. It could be an 18 or a 20.

There is no expansion plug on the side of the block. Are there other places I can look for ID?

[fleetwin]

OK, so you have a bit of a Frankenstein engine….The only place you will find IDs is on the block as you mentioned, and on one of the stern brackets….Post some pictures….
Is the ID plate still on the stern bracket? The last year for white Johnson Fds was 1966, does the exhaust housing appear to be of the same vintage as the stern brackets?

[amuller]

I will post some pics. Assuming it’s a ’69, the specified impeller housing is a 313543. What was in the motor was a 303070. The difference appears (I’ve not had the two in my hands to compare directly) to be that the 313543 has shorter "fins" in the drive shaft opening so the spacer can spigot in. This would account for the mickey-mousing of the spacer. Interesting is that if you do a search for 313543, and look a the pics of what people are offering on ebay, many of they are actually 303070. This, for example: http://www.ebay.com/itm/Johnson-Evinrud … 14&vxp=mtr

If this is so, I have a 303070 in decent shape and it might be converted by chucking it in a lathe and trimming the fins, or even just doing it with a dremel or die grinder. i think this is what Fleetwin was saying earlier?

On the other hand, I’m still noticing the four screw holes. Maybe it was machined to take either the metal or plastic pump? Could investigate this on the net until eyeballs fry without resolving it 100%.

[jerry-ahrens]

Heck, for what they want for a worn out impeller housing, I’ll bet you could get a NOS one for the same price. Check with club member Ed Elliot. He is in the directory. There are others in the club who sell new old stock parts as well. Those worn, grooved out impeller housings will pump weak at idle.

[amuller]

(Are these images too large and should I be shrinking them somehow?)

Anything here that would help pin down the identity of this motor?

Looks like something is missing from the top of the (green) shift/magneto interlock lever. What?

[Steve D]

quote amuller:

Anything here that would help pin down the identity of this motor?

Well assuming that shift handle is original, and the info at MarineEngine is accurate…I’ll say ’62-’67 18 horse Evinrude (I have to double-check a model-year guide but I don’t see a listing for a 20 horse). That style handle changed in ’68, and they don’t show a 25 until ’69.

But those years gear case cavitation plates (”62-’67) were more rounded, so it looks like someone installed a later gear case with the angles on that motor (it looks more greenish like from the ’69-’70 20/25 horse). That style seems to have started around the same time as the change to the more angular handles.

So like Fleetwin said, you have a bit of a Frankenstein, but that’s ok. Those parts work together ok for the most part.

Edit: Ok, so I stand corrected, I just came across a few ’69 Evinrude 25 horses that have the same style handle as yours, so I guess it’s possible it’s a 25 too. 😕

Handle style in 1968
upload a picture

[amuller]

I took another look at that shift handle. From the color, amount of wear, and so on it looks original to the motor.

Does anybody know, offhand, what parts differ from the 25 hp to the 18 and the 20? I did a little comparing, just for 1969, and the only part number differences I could find were for the cylinder head and the carb assembly. Couldn’t find any numbers on either that might serve to distinguish them.

Alan

[vintin]

I don’t know what other differences there are but one difference between the 1968 20hp and the 1969 25hp is the 25hp is exhaust tuned.

[Author]

Posts