Carburetor Size for Seak King 5HP

[drifter]

I’m in the process of saving a 5hp – 1957 Sea King – GG8960A (Gale 5D14) – from the salvage yard.
The carburetor was not salvageable as it was terribly corroded. The rest of the entire outboard shows almost no corrosion.

So, I rummaged through my spare parts and turned up an exact match…..well….almost.

The dimension of the original Sea King carburetor bore (where it mates to the intake manifold gasket) is .740".
The dimension of the carburetor from my spare parts is .805" at the rear bore.
Every other measurement is identical between the two carburetors.
The intake manifold hole diameter is .805" on the original Sea King 5hp manifold.
I’m thinking the replacement carburetor may be from a 7.5hp.

Will the replacement carburetor (with the slightly larger bore) function as well as the one with the slightly smaller bore.
Thank you for the help,
Drifter

[Doug Wilson]

may have to put a smaller jet in there but probably worth a shot

Doug

how is it motors multiply when the garage lights get
turned off?

[frankr]

How do the venturi (the restricted area in the middle of the bore) sizes compare? Even if it is larger, I’d try it and see how it works. Who knows, you may get another fraction of a horsepower out of it. "Jets" are not an issue unless the one you are contemplating using is a fixed jet model.

[drifter]

Thanks Frank. Your response about a "fraction of a horsepower" set me to thinking. So out to the garbage can to retrieve the plastic bag of the donor carb and sure enough it was marked CD12 (1955 Johnson 5.5hp). So, I compared the specs of the Johnson 5.5hp to the Sea King/Gale 5.0hp and they are identical (Bore, Stroke, WOT @ 4000RPM).
Is it probable that OMC got the extra 0.5HP from the ever so slightly larger carburetor?
Since I don’t have compression specs and I don’t know of any porting differences, and the mag is universal, that pretty much leave carburetor.
What do you think?
I’m a good ways from testing as I still have the rebuild to do and parts are just now arriving. But I am curious as to performance with the slightly larger carburetor (especially starting and idling).

[frankr]

I got to thinking also. I have a Gale 5 and a Johnson 5.5 sitting side by side. I see a considerable difference in the powerheads. Of course we all know the Johnson has a removable head, but I also see that the crankcase end is different. A look at the parts books shows that the Gale 5 actually has larger reeds! Imagine that! And they are not interchangable. The bolt pattern is different, and the carb sits higher on one. If I was a bit more ambitious this morning, I probably would have pulled the carburetors for comparison. I might yet.

[drifter]

Interesting. I have a 59, and a 62, Johnson and a 63 Evinrude 5.5 and never thought to look at them.
I am replacing one piston and I’m going to swap out the rod (with the Sea King rod) and put in new rings. I’ve already run the glaze breaker and the cylinders look great.
So, I have a ways to go before it makes noise.
I’ll post my findings when the smoke clears.
Thanks again for your help.
Nick

[1946zephyr]

I was about to say, isn’t that the same carb that goes on the 5.5’s?

[Author]

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