1964 40HP Seahorse fuel consumption

Reifwj

Seaman
Joined
Mar 23, 2010
Messages
58
How much fun per hour should I be using an hour trolling. I was idleing the motor in the tank in forward gear for about 3 minutes and used almost half a gallon. That's a gallon an hour trolling. Is that about right?

I set the idle in accordance with the top secret files and it runs like a top. If it is high consumption what could the cause be. Points and such of course, but what else? Thanks for your help.
 

bktheking

Vice Admiral
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Jul 29, 2008
Messages
5,057
Re: 1964 40HP Seahorse fuel consumption

Is the fuel pump tip top on the motor?
 

rolmops

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Feb 24, 2002
Messages
5,522
Re: 1964 40HP Seahorse fuel consumption

How much fun per hour should I be using an hour trolling. I was idleing the motor in the tank in forward gear for about 3 minutes and used almost half a gallon. That's a gallon an hour trolling. Is that about right?

I set the idle in accordance with the top secret files and it runs like a top. If it is high consumption what could the cause be. Points and such of course, but what else? Thanks for your help.

If in 3 minutes you use half a gallon,then in 6 minutes you use a gallon.
Try to put exactly one gallon in a small container and connect it to the system.Now try and idle again for 3 minutes in the tank.If you use half a gallon again this time there is something very seriously wrong with your fuel pump.
If you use much less this time around,check all your hoses for leaks.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 1964 40HP Seahorse fuel consumption

If your carburetor idle mixture is set at optimum, and it runs properly, what you get is what your get. bk has a valid point that if the fuel pump diaphragm is holed, it will get lousy gas mileage. But it won't run right either. That motor will burn about 4 gallons per hour at high speed. I really don't know what it should be at idle.
 

bktheking

Vice Admiral
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Jul 29, 2008
Messages
5,057
Re: 1964 40HP Seahorse fuel consumption

Like F_R said, he read my mind, ruptured diaphram in the fuel pump would cause double consumption but it would run like crap. Not sure on this motor, what cylinder drives the pump? Check spark plug condition.
 

Reifwj

Seaman
Joined
Mar 23, 2010
Messages
58
Re: 1964 40HP Seahorse fuel consumption

Sorry, My zero key isn't working. I used 1/2 gallon in thirty minutes.

I did have exactly one gallon in the tank. Brand new plugs.
 

bktheking

Vice Admiral
Joined
Jul 29, 2008
Messages
5,057
Re: 1964 40HP Seahorse fuel consumption

1/2 in 30 mins sounds about right, these motor aren't exactly "fuel efficient"

You can always substitute O for 0.
 

coolguy147

Commander
Joined
Jul 14, 2008
Messages
2,817
Re: 1964 40HP Seahorse fuel consumption

my 1961 mercury 500 seemed to be much more fuel effecient than my 1958 35hp johnson(simliar to yours). and the mercury goes faster :D
 

cougar1985

Lieutenant Junior Grade
Joined
Oct 7, 2005
Messages
1,023
Re: 1964 40HP Seahorse fuel consumption

my 1961 mercury 500 seemed to be much more fuel effecient than my 1958 35hp johnson(simliar to yours). and the mercury goes faster :D
had a merc exactly like that one .you could put a bolltle of beer on top of the motor while running slow and never foam it up,hows that for smooth,lol.
 

glassmaster68

Petty Officer 1st Class
Joined
Feb 17, 2010
Messages
227
Re: 1964 40HP Seahorse fuel consumption

my 66 40hp rude uses about one and half gal/30 min wide open,,and about half[ maybe a lil more] in 30 min at idle speed,so a half in 30 min at idle sounds pretty good,,,and like the king said,,,theyre not very fuel eff,,prob about 2 or three tenths of the fuel goes out the exhaust into the water,,and coug85,that does sound like a smooth runner,cant have elvis beer, all shook up,,uh,hu,,hey hey
 

coolguy147

Commander
Joined
Jul 14, 2008
Messages
2,817
Re: 1964 40HP Seahorse fuel consumption

had a merc exactly like that one .you could put a bolltle of beer on top of the motor while running slow and never foam it up,hows that for smooth,lol.

it really does not vibrate at all when at idle. i just realized that:p

the johnson man that would stir you up. pop pop pop pop pop. my steering system was constantly vibrating lol.

good engine though^
 
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