115 carbs on '75 merc 850 85hp??

countryboy26047

countryboy26047

Petty Officer 1st Class
Joined
May 25, 2012
Messages
303
Question, if I'm able to find a set of carbs off a merc 115, would they work on my 850?? The stroke, bore and all the other specs appear to.be the same... If it is possible, would it be worth it or would it cause me issues with being able to idle down and troll? Would be nice to get more top end, but I don't want to screw up the low end considering my 850 will troll all day long around 700rpms.. I also realize that my fuel economy would suffer, but would it be a drastic incline in fuel consumption?
 
C

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,142
Re: 115 carbs on '75 merc 850 85hp??

If you are discussing carbs off an inline 6, they are probably and exact replacement, but may have different jet sizes. Check part numbers for the 115 and an inline 4 for the same year to verify. I do not think you will change your power rating....... Inline sixes are really 3 inline 2 cylinder motors. Inline 4s are really 2 inline 2 motors. Each is fairly maxed out for power.

If you are talking about carbs off a 4 cylinder 115HP motor, that is a different animal. Some of those were 2+2 motors and would be unsuitable for you application, even if they would fit....
 
Faztbullet

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,616
Re: 115 carbs on '75 merc 850 85hp??

You wont gain any top end as the venturi size is the same, only things different are high speed jets and idle tube size...
 
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