adding a carb?

Red9654

Petty Officer 2nd Class
Joined
May 9, 2013
Messages
137
i have a chrysler outboard with a mechanical fuel pump that goes to a single carb. is it possible to add a second carb to it and how would i do it?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: adding a carb?

This Chrysler outboard is what HP, what year, and what model -- my crystal ball is broken again so I can't see it. And doing this would solve what? The motor was designed with a single carb for a reason: It doesn't need two nor would it likely run well as twice as much fuel and air is not a good thing. With exhaust tuning and extensive porting the second carb might add a few ponies. But first you would need an intake that supports two carbs and must fit that engine..
 

Red9654

Petty Officer 2nd Class
Joined
May 9, 2013
Messages
137
Re: adding a carb?

its a 1969 45 hp model 4545. and it would solve me doing this just to see what would happen
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: adding a carb?

No, it is not possible to add a carb and in reality, even if you custom made a manifold, you would not get much increased performance. In fact, you just may over-carb the engine and get really poor performance.

I modified a 55 Chrysler to accept a bigger carb and the engine simply would not run well with the added venturi area. It was over-carbed. You can search some of my posts about it on the Force/Chrysler forum. Search for "Say hallo to my leetle frand."

Don't bother wasting your time trying to add a second carb.
 
Last edited:

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: adding a carb?

If you are looking for more power buy a bigger motor, sell yours and look for a good deal on something else.
 
Joined
Oct 22, 2007
Messages
2,598
Re: adding a carb?

... in reality, even if you custom made a manifold, you would not get much increased performance. In fact, you just may over-carb the engine and get really poor performance.....

Here's the deal.... To have a good, consistent fuel/air mixture you need to have a certain minimum airflow velocity through the venturi. By adding a second carb you'd be roughly cutting the velocity in each carb in half, which would be a disaster for your fuel/air mixture.
 
Top