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nzjetboating.com Forums => Engines => Tech Library => Fuel System and tanks => Topic started by: Brendan on October 20, 2010, 20:36:52 PM

Title: water in the fuel
Post by: Brendan on October 20, 2010, 20:36:52 PM
Hi all, this may be of help to some of you, after lots of flooding problems i located the cause, water in the fuel. there was enough to fill the water trap then pass into the carb. The solution, i fitted a water trap to the tank breathers. problem solved.

the upper trap in the pics is for the breathers, the lower one is the fuel water trap
Title: Re: water in the fuel
Post by: Tonz on October 20, 2010, 21:44:53 PM
Outstanding idea b>
Title: Re: water in the fuel
Post by: Brendan on October 21, 2010, 17:55:36 PM
i originally fitted it to see how much water was getting in, it is amazing how much does get in, it even traps the condensation.
Title: Re: water in the fuel
Post by: Irish on October 22, 2010, 11:47:50 AM
Also if you know or think there maybe a little bit of water in the fuel be it from condensation or whatever, pour a a bottle of meths into tank to absorb the water that still might be lurking. Even with the breathers there still might be some water build up, especially if you havnt used the boat for a while, if regular fresh fuel going in it shouldnt be a problem. Meths will help but still try and resolve the problem if its not just condensation.
Title: Re: water in the fuel
Post by: Brendan on October 22, 2010, 22:39:15 PM
cheers Irish, the old meths trick works well, i put it in most of the time,  i havn't had water in the fuel trap for a while since fitting the breather trap (6months ago)
Title: Re: water in the fuel
Post by: Anarchy on October 24, 2010, 22:46:45 PM
meths ? do you put it in with your fuel or are you flushing the tanks with it  ??? ??? ???
Title: Re: water in the fuel
Post by: Brendan on October 25, 2010, 08:56:34 AM
 i put the meths in the fuel, about 500ml of meths to 30 L of fuel. it doesn't seem to affect the engine perfomance with that mix
Title: Re: water in the fuel
Post by: johnmead on October 25, 2010, 12:50:22 PM
I had a settling bowl like in Brendan's picture, and had to empty water out of it every time the boat was used for years, and then I moved the breathers from the top of the transom up to the top of the engine cover behind the back seat and never saw water in the bowl again. Now with the new motor I have a Delphi set-up with proper filter to catch anything, and also a in-line filter between pump and injector rail.
Title: Re: water in the fuel
Post by: Gunny on October 28, 2013, 08:58:03 AM
I have just done a search on this topic and found this old thread, good to know some tricks. I experienced a problem yesterday with what i thought was lack of fuel, as in, run out!  We topped up up and carried on but the engine coughed a couple of times. Their is a fuel bowl and on inspection once home it was full of water, about 5 mm fuel on the top! Arrrgh! I wondering if there might be a bit of waer got through into the carb and what should i do to get it out? Will the meths trick get anything out of the carb if it is there? My breathers are at the back on top of the transome so might have to make a change. Cheers
Title: Re: water in the fuel
Post by: SDH on October 28, 2013, 09:09:31 AM
Best just to drain the carb completely to remove any water. The meths works well in the tank. The breathers on the transom tend to get water in the from backing, hammy turns, sudden stops etc.
Title: Re: water in the fuel
Post by: Gunny on October 28, 2013, 12:10:25 PM
ok will try that. next question...how do you drain the fuel from the carb? 4 barrel holley. No glaringly obvious drain plug, so not wanting to start unscrewing bits, any hints?
Title: Re: water in the fuel
Post by: Paul on October 28, 2013, 15:59:15 PM
ok will try that. next question...how do you drain the fuel from the carb? 4 barrel holley. No glaringly obvious drain plug, so not wanting to start unscrewing bits, any hints?

Easiest thing is to take the carb off (4 bolts on manifold) and turn it upside down.  The internal holley gaskets (like bowl gasket) aren't cheap. The intake manifold gasket can be re-generated with some thick paper if needed (- spray gasket liberally with silicon when re-assembling it so it comes off easy next time).

Can also remove the side mounted bowl  fuel-level-plug, to drain, once it's removed from engine.
Title: Re: water in the fuel
Post by: tmack on November 01, 2013, 16:16:02 PM
The fuel bowl gaskets for the 4 barrel holley are only about 6 dollars each. I found it just as easy to take the fuel bowls off, saves undo-ing the fuel lines,throttle etc.
Title: Re: water in the fuel
Post by: Gunny on November 04, 2013, 09:24:53 AM
where is the best place to get the gaskets from?
Title: Re: water in the fuel
Post by: tmack on November 30, 2013, 17:31:32 PM
I just get mine from Automotive Engine Reconditioners in invercargill