mercury 115 with water in fuel

i have a 1986 mercury 115. i just bought the motor and hung it on my boat. i rebuilt the carbs and replaced the water pumpo and switch box. i ran it in the driveway and it ran good i went to the river and backed down the ramp. i tryed to start it and it would not start. the fuel filter was very milky. i dont under stand were the water is coming from. i took the boat home and drained the carbs. once again it ran great. i headed back to the river and i had the same thing happen. where could this water come from?????? the fuel pump??
any help would be great. thank you

Re: mercury 115 with water in fuel

Water is heavier than fuel. Perhaps when you back down the ramp, the water collects neat the fuel pickup.

You should jack up the trailer tongue and siphon some fuel out of the tank thru the gas gauge sender hole to get out the water. Put it in a clear container so you can see what you have.

Re: mercury 115 with water in fuel

It's coming from the Gasohol in your fuel tank. Ethanol is notorious for sucking up water, which outboards surely don't like!!

You'll probably need to drain and flush your entire fuel system. A fuel/water separator filter might be a worthwhile addition.

Additives such as Seafoam or any of the outboard motor mfr's fuel conditioners will help.

www.seafoamsales.com

If you have a built-in tank, the fuel can suck water vapor from the air in extended storage periods. If you leave sit for more than a few weeks, you probably need to add a fuel stabilizer such as Sta-Bil or Star brite (Star brite also sells several types of fuel cleaners/conditioners).

http://www.starbrite.com/prodcatalog.cfm?ProductCat=Marine&ProductSCat=Gas and Diesel Additives

If you have a portable tank, you may have just gotten gas with a big slug of water in it. All the more reason to hate Ethanol in outboards!

HTH & G'luck.........ed

Re: mercury 115 with water in fuel

Gasohol, anywhere near water, (like in a boat) will attract the water and then the alcohol and water will drop out. That chit doesn't burn. It is home for all kinds of microcritters that make a sludge to plug things up. Even if you sort it out with a fuel/water seperator, the gas that's left is low enough octane to grenade yer head.

For that reason, unless you plan to run it dry within a day, don't put gasohol in the boat. Use the 92 octane classic car gas instead. If you're going to leave it in the boat over a week or 2, add 2 ounces of StaBil to it for every 5 gallons of gas.

For now, muck out the mess and start over.

Hope it helps.

Re: mercury 115 with water in fuel

hey
thanks for all the info......i will give all suggistion a try this week and will post my results. thanks again!

Re: mercury 115 with water in fuel

a friend of mine give me this paste that if you dip in tank and water is present it will turn color. my tank had no water! i tested the milky stuff in my fuel filter and it was also not water. i cleaned the fuel system and ran from anouther tank and it ran perfect. thanks for all your help you guy are great. and i will deffinatley be using a fuel additive!