1954 Evinrude Big Twin 25 HP serial 25916 carb questions.

[NateFoerg]

I am new to these engines, boat engines in general actually. I am however well versed in vintage 2 stroke motorcycle motors.

Can anyone answer the following questions-

1. If fuel is Leaking (pumping) out of a small overflow hole at the top of the carb, is this a float/needle not being able to keep the fuel at the proper level and thus overflowing problem? I have a carb kit on order, but in the interim, I cleaned the seat. The needle has a substantial groove in the tip where it seats, and in my expiernce, this is not good...

2. where can I get a replacement main nozzle? the brass tube that feeds gas up from the float bowl? Mine has broken off the tangs that make up the screwdriver slot.

3. what is the correct ratio Gas/oil for this engine?

4. Anyone know where I can find a manual/parts list? I have been searching all over, and not had any luck yet.

Thanks!

Nate in Ann Arbor MI

 

[MTboatguy]

Do a search on google, for Evinrude 439074, which is the number for the carb kit for that engine.

You can get an owners maintenance manual right here on Iboats:

http://www.iboats.com/Evinrude-25-hp...view_id.438897

Iboats also carries the service manual for that engine:

http://www.iboats.com/1953-1954-Evin...view_id.438915

If I remember correctly, the original fuel mixture on that motor was 24:1, but with the modern TWC oils you should be able to mix at 40:1 and be fine, I am sure if I am remember incorrectly, some one will chime in with the right information on the mixture.

 

[NateFoerg]

Owners manual ordered. Thanks.

Anyone have input on Q's 1 & 2?

 

[MTboatguy]

Well in my experience, if the needle is grooved that bad, then it is not shutting the fuel flow off like it should and allowing the carb bowl to over fill, which is causing the fuel to leak out the overflow. As far as where to get a replacement main, I would say, take a look on ebay or if you have any boat motor salvage yards in your area, start calling them. These days, I don't rebuild my carbs, I just look around and find one that has been rebuilt by a pro and purchase a new one.