Gas leak in Evinrude carb.

wb5tka

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Jul 13, 2001
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96 Evinrude 150 hp V6 has one of the carbs leaking gas by the slow speed mixture screw. Only when engine is running. The leakage is enough to run down and onto the other carbs below. I verified that no other carbs are leaking.<br />Questions: What would cause this, of course? Is that an air mixture adjustment? If so, no fuel should be inside that area, right? If there is supposed to be fuel inside, is there some sort of gasket/seak inside that this needle valve screw passes through? Last question: What's needed to fix it?
 

clanton

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Jul 9, 2001
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Re: Gas leak in Evinrude carb.

I think there is a fuel manifold close the screw, o-rings may be leaking.
 

12Footer

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Mar 25, 2001
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Re: Gas leak in Evinrude carb.

It's leaking from the screw itself? That is odd. Usually, they are too tight at the threads to leak. It is iether about to fall out from being to loose, or Clanton is right-on about the o-ring.<br />I would screw it in until it gently seats while COUNTING the turns.<br />Then, you can remove it and check the seat.<br />I do not have the initial carb adjustment for your engine, but if you must turn it in more than 3 complete turns, I'd say it worked-loose.
 

wb5tka

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Re: Gas leak in Evinrude carb.

I tried screwing it in - as the manual aluded to when putting a rebuilt carb back in place - all the way to the end and then to back it out two turns. I screwed it in, but it never seemed to never really tighten, as though it was stripped. I didn't want to overdo it. I removed the screw completely and it did not seem to be that "tight" in its travel. The threads didn't look obviously damaged, but they do look very fine pitched. As far as I know, this screw has never been removed before. I'm the original owner of the motor and I've never worked on it before.
 

clanton

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Re: Gas leak in Evinrude carb.

I am looking at diagram of this carb. The fuel manifold and plate that covers carb passages are close to the idle screw. wiggle the maniflod while engine idleing . Does it stop? Float stuck? Float gasket ? Split in carb body?
 

clanton

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Re: Gas leak in Evinrude carb.

I am looking at diagram of this carb. The fuel manifold and plate that covers carb passages are close to the idle screw. wiggle the maniflod while engine idleing . Does it stop? Float stuck? Float gasket ? Split in carb body?
 

wb5tka

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Re: Gas leak in Evinrude carb.

Yes, the spring is in place. One thing curious, the book said to screw it in all the way and back it out two turns. I tried that and it never seemed to get tight as though it had reached the "end". I was afraid to try tightening it in further for fear that the threads might strip or I'd ruin the needle end. The treads look very, very fine pitched. More so than I would have expected.
 

wb5tka

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Re: Gas leak in Evinrude carb.

Clanton, where can one obtain a copy of that diagram? That would help me immensely.<br />Does it show that gas should be present in the two chambers that pin (needle screw) passes through?
 

Beernutz

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Aug 14, 2001
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Re: Gas leak in Evinrude carb.

I've just been introduced to this site, and probably too late. Any way, your carbs should be of the black plastic body variety. Are you certain of the location of the leak? Floatbowls have a built in leak defect. On the starboard side of the lower portion of the bowl, you'll find a stainless ball pressed into a recess where the bowl was cross-drilled when manufactured. Over time these balls loosen and start to leak, sometimes profusely, all over the carb below and down the front of the lower unit. Also causes foul running at startup, while that portion of the bowl refills. I've been able to seal some by tapping the ball back in, and sealing it with 3-M weatherstrip adhesive. Might be worth a look.
 

wb5tka

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Jul 13, 2001
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Re: Gas leak in Evinrude carb.

Thanks for all the ideas offered on this problem. I purchased a rebuilt kit and after rebuilding that carb the leak is gone for good. Reafirming my original conclusion as to where the gas was flowing from, it was from where I said it was. It was not hard to come to that conclusion.<br />Anyhow, I'm back in business with no more leaks and the motor runs fine.
 
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