1969 25HP Evinrude Fuel Pump: Will newer pumps fit/interchange.

[LK_Shastina]

Hello. It's time to change fuel pump on my 69 Evinrude 25hp Sportster.
My question is, will other, newer fuel pumps fit and work on this engine? The mounting holes look the same on newere 25hp Evinrude/Johnsons.
Before you say "Just buy the right OEM fuel pump, know that I ask because the OEM pump apparently, according to part number and selection, is $100+ Yet there are $25 or less aftermarket pumps available for other Evinrude models of same era of various HP. It's a square pump, looks just like the one that fits up to a 15hp Evinrude, but perhaps the output is different in pressure or volume?
I also ask, because sometimes you break down on a fishing trip a long way in space and time from the exact replacement part you need. But with the right information, another part that just happens to be handy, occasionally at midnight, will fit and work just fine, and the possession of such knowledge will make one a hero to one's fishing trip buddies, kinda like that old seasoned but cooked medium rare mechanic that haunts these forums.
*Not! implying that he's ever shopped at the Midnight Special Part Store, not without permission anyway.
Hoping an experienced outboard mechanic might know the answer to this.

PS: My real issue is ethanol in gasoline destroying fuel systems on all sorts of my 2 stroke stuff. Heck, this motor will supposedly run on kerosene, maybe I'll just switch to it.

 

[F_R]

The mounting holes are the same on all of them. And the output is comparable. So, if it fits in the space, and the hoses can be routed without interference, it will work.

 

[racerone]

A new diaphragm at $ 5.00 will likely fix your pump.---And yes that diaphragm is available at the dealer.--I visited an E-bay site where they have the VRO pumps listed at near factory price .----Note says around 1700 sold.------I guess folks are quick to blame fuel pumps and is the first item to replace in trouble shooting.

 

[oldboat1]

Big believer in oem parts, rebuild diaphragms or kits too, but the aftermarket pumps are in the $15 - $20 range (often with free shipping) -- find that too cheap to pass up. Bought one last year, and seemed to be fine. Heck, buy two or three (fishing camp).

Some are taller than others -- extend out further. Check what you have, and buy similar.

 

[LK_Shastina]

Thank you all for the responses & valuable advice! I don't have a yard littered with 'Rudes & Johnsons, so cant just open stuff up and invesigate.
Interesting that the pump mounts are all the same, (as I suspected).

 

[LK_Shastina]

Follow up:
So I bought a replacement fuel pump for a whopping $15.- More out of curiosity than frugality. According to latest Googled info the new pump, # 397838 supercedes most pumps from same era, including the unique one 25hp Evinrude Sportster.
But, as shown in photo, new pump is taller than original. It has the base of the later mid-70s & up pumps, but the old square housing. And a few extra parts. Also, the inlet gasket has 1 hole larger than the other 3. The original had 4 large holes. I had to buy two longer screws to mount it. The new carb's metal parts are anodized aluminum, not stainless steel.
I'm really curious to see what's different inside. But I learned that lesson 30 years ago by taking all 4 screws out to remove the pump from the engine. It took hours to find all the little innards that flew out all over the driveway, and the search for and purchase of a manual to tediously get it all back together in the right order. I'm betting that their fuel pump design engineer hit it rich years later with his invention of the Rubics Cube. Lesson learned. I read the manual first now. Or at least study the photos like a 15y old...
The 25hp Sportster has a small streamlined hood, and at first I thought maybe that's the reason for the compact pump body, but the hood fits. I don't know how much the engine shakes on the rubber mounts, so it could possibly rub? If so, I suppose I could install a sideways hood scoop. I'm waiting on a few more parts, so I haven't run engine yet to test the new pump's output pressure and volume.

As a side note, I had also taken the carb apart to rebuild it because a bad batch of local gas destroyed the fuel lines and those every single piece of 2 stroke equipment I and all my neighbors own over the winter. Even my truck's tank mounted fuel pump failed. It was a Silent Spring around here (cursing excepted). Interestingly enough, carb was absolutely spotless inside. I was surprised, as it had not been opened up or removed from the engine in 50 years. I was kinda proud to own such a jewel, and even showed it off to my neighbors. As I later read, they treated the carburetors with something to seal and protect the metal from corrosion. So never soak them with harsh carb cleaner (not that you can buy the good skull & crossbones stuff anymore) and do not scratch them inside while cleaning. Doing so will most likely lead to to severe corrosion issues over the next 50 years.

 

[Crosbyman]

I installed on of those thicker based pump....with longer screws on my 6R74 evinrude

I will be testing it in a few weeks but by the looks of it I feel confident.... but I am keeping my old pump around

the pumps aren't that bad to rebuild with kits (done a few)

http://www.leeroysramblings.com/Rebuilding_fuelpump.htm