Preventing moisture/water in fuel

pwstephe

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Joined
May 25, 2003
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2
Experts:<br />I have a 40 HP Johnson 2 cycle outboard conencted to a plastic fuel tank with new hoses. The engine was tuned 2 weeks ago and when we put the boat in for the season it ran very well.<br /><br />After 2 weeks of inactivity it is very difficult to start and stalls. I suspect that this is a fuel problem and most likely moisture in the fuel. We have had a lot rain for the last two weeks. (and the Missouri fuel I purchase contains 10% ethanol.) <br /><br />The tank vent and cap were closed but somehow moisture is still getting into the fuel. I have had this problem mutiple times in the past and I need some fundamental advice about combating moisture buld up.<br /><br />Questions:<br />1). Would a metal fuel tank minimize moisture build up?<br />2). Should I install a Water Separating Fuel Filter?<br />3). Should I be adding fuel additives to eliminate moisture on an on-going basis?<br />4). Should I cover the fuel tank and engine when not in use.<br />5). Should I move to Arizona?<br /><br />Thanks! :eek:
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Preventing moisture/water in fuel

Hi, Phil.<br /><br />Ethanol is bad for older carbs and fuel pumps. What year or model number is your engine?<br /><br />One of the problems with ethanol-enhanced gasoline is that the ethanol will absorb water and seperate from the gasoline. Some have recommended adding acetone (like HEET), but it is even worse on rubber parts than ethanol.<br /><br />My opinion is that the best solution is to never use ethanol or methanol enhanced gasoline unless the Owner's Manual specifically says it is okay, and to add a water seperating filter to the system.<br /><br />Good luck. :)
 

pwstephe

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Joined
May 25, 2003
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Re: Preventing moisture/water in fuel

JB,<br /><br />Thank you for the response. The Johnson 40 is a 2002 model but I don't see a model number even in the Operation & Maintenance Manual.<br /><br />In the manual the OMC people say using an Ethanol fuel is only acceptable if it no more than 10% in volume but I'm sure you are correct that Ethanol attracts moisture. I think that in Missouri by law I am unable to find a gasoline source that is Ethanol free but it does not exceed 10% by volume.<br /><br />I like your Heet idea since it should cause water to become soluble in gasoline but I never knew if it was applicable for gas oil mixes.<br /><br />Thanks,<br />Phil
 

neumanns

Lieutenant Commander
Joined
Mar 1, 2003
Messages
1,926
Re: Preventing moisture/water in fuel

I have been told also to stay away from oxyjenated fuels as they have a longer shelf life and do not break down as easily and have been told to find out if someone around carries unleaded that is classified as off road... the offroad fuels are nonoxyjenated and do not contain ethanol but perhaps you could get more input on this subject as I have no expertise on the subject only hearsay but trust who told me<br /><br />sorry no help on your wter problem
 
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