Gas Leaking from Exhaust

[hetheride]

Hi All,<br /><br />I am new to this forum and hoping you can give me some insight-<br /><br />I recently purchased a fishing boat with an old (1973) Evinrude on it, the first day it ran great-no problems.<br /><br />The second day, I proceed to leave the dock and it dies on me, I check the gas can and its empty, I refill it proceeds to dump itself into the water again. <br /><br />I take it to the new marina on my lake (bad move) and he rebuilds carbs, and its still doing the same thing. He says when you squeeze the bulb gas comes out of the exhaust. Due to some other things I choose not to let him diagnose the issue...so I am back at square one.<br /><br />Any idea why the gas would be flowing through to the exhaust and dumping into the water? I am planning on taking it in to another marina but thought I may want to educate myself a little bit first. Any info is greatly appreciated.

 

[Dhadley]

Re: Gas Leaking from Exhaust

We assume you dont see any external leaks like a broken hose or gas squirting out of the back of the fuel pump. Might be a good thing to check as someone squeezes the bulb. Hard to believe a tech gave it back and didnt fix what he knew was wrong.<br /><br />Anyway, a couple of things come to mind. Probably a long shot but -- if the fuel pump is lesking internally its possible it could be getting into the pulse hose connected to #4 cylinder. <br /><br />The obvious thing is the carb floats but you said the carbs were rebuilt. It might not hurt to remove the carb silencer cover and just see if gas comes out in the carb throat as the bulb is pumped.<br /><br />Good luck!

 

[hetheride]

Re: Gas Leaking from Exhaust

Thanks for the info, <br /><br />When you said #4 Cylinder, help me out here- this motor is a 2 cylinder...could this still be the case?

 

[Dhadley]

Re: Gas Leaking from Exhaust

Oops!<br /><br />Sorry! I don't know why I was thinking about a V4 for some reason. Anyway, yes the pump, in theory, could leak back to the cylinder it gets the pulse from. <br /><br />What motor is it?

 

[hetheride]

Re: Gas Leaking from Exhaust

Thanks for the input, The motor is a 50HP 1973 Evinrude.<br /><br />I dropped it by another marina this morning and am hoping that they can find and fix the problem. However, they are on a 1-2 week wait.<br /><br />Any other advice would be appreciated.

 

[Dhadley]

Re: Gas Leaking from Exhaust

Well, if you still have access to it you could look at the fuel pump. There are 3 hoses. Fuel in from the tank. Fuel out to the carbs. And a third line thats a pulse line. It goes to the crankcase where the piston going up and down (actually forward and back) creates the pulse that operates the pump.<br /><br />If the pump was leaking internally you could remove the pulse line from the pump and squeeze the bulb in the fuel line. No fuel should come from where you disconnected the hose.<br /><br />If you get fuel coming out there the pump is bad and needs fixed or replaced. I'd replace it as there have been a couple of changes since 1973.<br /><br />If it doesnt leak, the bulb should become very firm quickly. If you can continue to fush fuel thru easily, I would suspect a problem with the needle and seat in one or both carbs.