Possible Carb Problem

AguaSki

Chief Petty Officer
Joined
Jul 4, 2005
Messages
545
My motor is a 1978 Johnson 140 hp. Today I was doing some summerizing and noticed that a piece of my carb broke where 1 of the 4 silencer bolts mount. Specifically it is the lower port side bolt. It was hard getting a camera into the area, but below is my best pic. It looks to be just the threaded portion that of the carb that receives the silencer bolt has completely snapped off. This allows extra air to get into the barrel behind the gasket. You can see in the pic that the upper bolt is fine. Both bolts on the starboard side are also fine. I don't know when this occurred, but I assume I must have used the boat with the carb in this condition for a good portion of last summer. There has not been a noticeable change in performance, and everything seems to be running perfectly. Can I continue running my motor with this piece of my carb broken off? Eventually I will replace it, but I just want to gauge how significant of an issue this is.

IMG_1016.jpg
 

71Windsor

Petty Officer 1st Class
Joined
Jun 25, 2008
Messages
286
Re: Possible Carb Problem

Your engine more than likely seemed to run fine becuase the other carb is still acting fine. However having any leak what so ever would cause your engine to run lean on those cylinders. Though if it were a significant leak I would imagine you would see fuel leaking down the side of the carb and that would be bad. You do not want to run your engine with less fuel. Less fuel is less oil. So in my opinion I would not run your boat with that problem until you remedy this.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Possible Carb Problem

air leaking between air silencer will do no harm. there are many motors running without silencers, that have never been put back on.
 

AguaSki

Chief Petty Officer
Joined
Jul 4, 2005
Messages
545
Re: Possible Carb Problem

air leaking between air silencer will do no harm. there are many motors running without silencers, that have never been put back on.

That is what I was thinking when I posted the question. Just a little air is getting in behind the silencer. No fuel leakage at all. I will leave it alone for now and then replace the lower carb body during the next rebuild.
 
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