Where to find vintage bypass cover for fuel pump conversion on an old OMC?

[tinkertinker]

Hi folks,

Still working on my 1957 Evinrude 35hp Bigtwin, electric start. She runs! She shifts! She spits water! And I haven't really even cleaned the carb yet. : )

Installed new impeller, fuel bowl gasket, repaired 2-line tank hoses.... but after reading LOTS of info here, interested in going to a fuel pump. The easiest path seems to be the fuel pump conversion using the bypass cover made for very similar motors in the late 50s and early 60s.

Anyone have a part # and source for the bypass cover and appropriate pump? Thx!

BTW- anyone thinking of doing this should read the very interesting pro/con arguments on this board. Enlightening! Do a search.

 

[jay_merrill]

Re: Where to find vintage bypass cover for fuel pump conversion on an old OMC?

You can also drill/tap the bypass cover that you have. If you do this, you may have to mount the pump upside down, in order to clear the throttle rod that is just under the armature plate, on the port side of the motor. It just depends on which pump you use.

The bosses where the pump is mounted, are already on your bypass covers. On the ERude and Johnsons, they were never used. All you have to do is to remove the top cover, drill the center all the way through and then drill/tap the outer pair, for the mounting screws. Don't drill the outer two all of the way through. The reason why some of the new pumps will hit the throttle rod, is because the bosses on the original covers are very slightly higher, than is true of the later bypass covers.

Here's one of my '58 Bigtwins with an original bypass cover.

Here's the other, with a Johnson 33 hp cover used in place of the original.

???

 

[F_R]

Re: Where to find vintage bypass cover for fuel pump conversion on an old OMC?

The 35hp should already have bypass covers for a fuel pump. You just have to drill and tap one of them.

It is my understanding that the 18-7351 pump sold here at iboats will mount and clear in the right side up positon. Will somebody please confirm or deny this?
http://www.iboats.com/Fuel-Pump-for...3128246--**********.180118021--view_id.174140

EDIT: The attached picture is INCORRECT. You should tap the threads 10-24, NOT 10-32.

 

[tashasdaddy]

Re: Where to find vintage bypass cover for fuel pump conversion on an old OMC?

exactly http://forums.iboats.com/showthread.php?t=205628

 

[tinkertinker]

Re: Where to find vintage bypass cover for fuel pump conversion on an old OMC?

Thanks, everyone.

Sounds like I might want to find a spare bypass cover to be my frankenstein, just in case I mess it up.

Inspiring advice, though, and tashasdaddy even has pics! Looking forward to giving it a whirl.