Gas leaking at carb

[zealer]

Hey all,

I have some more boating woes. Had the carb rebuilt a few days ago, slapped it on the other day, everything ran fine with no leaks.

Today, after just starting the engine I immediately noticed fuel dripping out from the inlet to the carb. Any thoughts as to why this would all of a sudden happen? The threads are not stripped or cross-threaded, as near as I can visually tell anyway. I undid the line and did it back up to see if maybe it was in right, all the way etc, but still didn't stop the leak. I presume it is gonna cost me some $$ to get a new line and inlet nut...

If you want to see a really exciting video of the culprit area, check here: Gas leak - YouTube
Boggles my mind that this started happening :blue:

P.S: leaks when engine running and right after (until pressure bleeds off). video is when engine is off, 30 secs after shutdown.

 

[Texasmark]

Re: Gas leaking at carb

What kind of fitting is on the end of the hose? Do you have a threaded nut that slides over the hose and then the hose is flared (female) and looking into the silver block to which it attaches you see a flare male looking at you?

If you look at both flared surfaces and see they are without scratch marks, you start the nut into the block fingers only and it goes easily for most of the distance (wiggling the fuel line while doing this this is ok), and you did not try to put any kind of seal/sealer between the two joints, then get on both with suitable wrenches and tighten the nut until it just stops leaking.

For a flare seal to work you have to have enough pressure on the joint to ensure that any minor imperfections in the mating area are pressed together with enough force to keep fuel molecules from leaking past.

Mark

 

[zealer]

Re: Gas leaking at carb

It is indeed a flare seal. I did the exact method you described above and thought I tightened it pretty well. I'll try and see if I can put some more muscle into it tomorrow.
Cheers

 

[Jonnybbad]

Re: Gas leaking at carb

That looks like the carb on my 3.0L. I had the same problem and had to tighten the bejesus out of it to get it to seal up. It makes me not want to take the carb off again for fear that I won't be able to get it to seal again. Then I'll have to buy or make a new gas line and probably get a new one of the inlet nut deals.

 

[Don S]

Re: Gas leaking at carb

Disconnect the fitting and check for dirt or a crack in the flare. "tightening the bejesus out of it" is not the best thing to do, really close to the worst thing you could do.