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9,9hp/15hp Carburetor Venturi Question

joereeves

joereeves

Gold Medal Contributor
In going thru my remaining stock, selling on eBay (eventually hundreds of parts) under my "sellers" name (Joe_OMC32) should you want to check it out... I came across one new and one used 15hp (I think) carburetors. The part number of 390773 indicates they're 15hp carbs, but I'm still not sure as I could have stuck them in the wrong box (or a old box), then forgot about them.

Measuring the venturi, actually the hole in the back of the carburetor where it meets the intake manifold, I come up with approximately 15/16"... perhaps just a hair over 15/16".

Does anyone know the the sizes of the (rear) venturi/hole of the 9.9hp in comparison with the 15hp? If so, I'd appreciate having you pass it on to me. That would pin it down for sure.

The confusion arises due to the 9.9 "Sail" carburetor and the 15hp "Sail" carburetor being the same.
 
If they are the metal carbs they are easy to tell apart. The 9.9 carb has the tube that runs through the venturi, The 15 hp carb does not have that.Otherwise I can measure a 9.9 for.you tomorrow.
 
flyingscott said:
If they are the metal carbs they are easy to tell apart. The 9.9 carb has the tube that runs through the venturi, The 15 hp carb does not have that.Otherwise I can measure a 9.9 for.you tomorrow.
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I appreciate that Scott (measurement). I have both carbs sitting on my computer desk... the only thing in the venturi is the high speed nozzle tube.

If you're speaking of the smaller brass tube that runs thru the high speed nozzle to feed the top slow speed passageway... that isn't present on these carbs. Keep in mind that I retired in 1991 which pretty much dates these two items.
 
Not yet I am on call this week so tonite was a late one, tomorrow for sure. I am positive the 15 hp carb has only the high speed nozzle in the venturi. The 9.9 has the tube running through the venturi to the low speed circuit.
 
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flyingscott said:
Not yet I am on call this week so tonite was a late one, tomorrow for sure. I am positive the 15 hp carb has only the high speed nozzle in the venturi. The 9.9 has the tube running through the venturi to the low speed circuit.
Click to expand...

Hmmm... In which case, I have two 15hp carburetors here. I'll standby and await your 9.9 measurement.
 
Hello Joe, My 9.9 carb is 1 1\8" opening on the airbox side and 1" on the other side. I did look at my 15 hp and there is no tube up through the center like my 9.9 does.
 
flyingscott said:
Hello Joe, My 9.9 carb is 1 1\8" opening on the airbox side and 1" on the other side. I did look at my 15 hp and there is no tube up through the center like my 9.9 does.
Click to expand...

That's pretty close to what I have here (1-3/16 air-box and 15/16" manifold) which could very well translate to your measurements (my wood ruler isn't exactly the finest measurement device). I appreciate your efforts my friend.

But yet, my carburetors DO NOT have the small S/S brass fuel feed tube... just the H/S nozzle alone. From what I gather, my carburetors 390773 fit the 1979 15hp alone, then both the 9.9hp (Sail) and also the 15hp (Sail) from 1978 thru 1988 depending on what H/S jet is used #45 = 9.9hp... #56 = 15hp... #54 = 9.9hp & 15hp Sail.

At least that's what I come up with according to my books. However I always thought that the venturi was different between all of the 9.9's & 15s.

Both my carburetors (New & Used) have the number 388275 imprinted on top of them which usually means nothing... I'll check into that tomorrow.
 
joereeves said:
In going thru my remaining stock, selling on eBay (eventually hundreds of parts) under my "sellers" name (Joe_OMC32) should you want to check it out... I came across one new and one used 15hp (I think) carburetors. The part number of 390773 indicates they're 15hp carbs, but I'm still not sure as I could have stuck them in the wrong box (or a old box), then forgot about them.

Measuring the venturi, actually the hole in the back of the carburetor where it meets the intake manifold, I come up with approximately 15/16"... perhaps just a hair over 15/16".

Does anyone know the the sizes of the (rear) venturi/hole of the 9.9hp in comparison with the 15hp? If so, I'd appreciate having you pass it on to me. That would pin it down for sure.

The confusion arises due to the 9.9 "Sail" carburetor and the 15hp "Sail" carburetor being the same.
Click to expand...
9.9hp inside dia of actual venturi is .625 and 15hp is .875 from my research.
 
That sounds correct, but I'm not home to check. I have two 9.9's that I want to convert. I have many extra 9.9 carbs. Converted many over the years. Minnesota has a 10 hp limit on many border area lakes. The conversion has been popular over the years among fisherman as well as guides like myself.
 
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joereeves said:
In going thru my remaining stock, selling on eBay (eventually hundreds of parts) under my "sellers" name (Joe_OMC32) should you want to check it out... I came across one new and one used 15hp (I think) carburetors. The part number of 390773 indicates they're 15hp carbs, but I'm still not sure as I could have stuck them in the wrong box (or a old box), then forgot about them.

Measuring the venturi, actually the hole in the back of the carburetor where it meets the intake manifold, I come up with approximately 15/16"... perhaps just a hair over 15/16".

Does anyone know the the sizes of the (rear) venturi/hole of the 9.9hp in comparison with the 15hp? If so, I'd appreciate having you pass it on to me. That would pin it down for sure.

The confusion arises due to the 9.9 "Sail" carburetor and the 15hp "Sail" carburetor being the same.
Click to expand...
(6 years behind the conversation....) Still have any of those new/used 15hp carbs? thinking of the making the same conversion.
 
schreiberpd said:
(6 years behind the conversation....) Still have any of those new/used 15hp carbs? thinking of the making the same conversion.
Click to expand...
Hi, I might have one left. Bought these from Joe and I think I only used one of them. I'll have you PM me if you can. Thanks, Tim
 
Got one here. They are getting hard to find. Will maybe have to change prop too. What year the motor?
 
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