Water Separator

[captainjohn]

I'm getting service done on the Nissan 40 hp 2 cycle on my Mac19 and the dealer insists that he install a water separator filter on the boat to prevent future problems. He says he adds these to even small inflatable outboards. Problem is, I'm not sure where to put it on the boat where it won't present a hazard or trip factor. I've heard of water sepatators on diesels being important, but never really thought they were necessary for regular outboards. Anybody have experience with this? I'm in New England and the gas is pretty clean here.

[Paul S]

I was thinking of doing it on our 04M, but have not found a location where it would NOT be in the way! It has been fine for the past few years, so I am not going to lose sleep over it!

Also, have you joined the North East Trailor Sailors yet? If not, you should. We have a lot of group outings during the year. In a couple of weeks we will be having our annual Christmas party as well. With over 120 members now, you will have a good local network (in addition to this forum) for any help you might need!

Also, it would be helpful if you put your boat information in your profile

Paul
webmaster
ne-ts

[Deeseas]

Captainjohn
I've had my Mac 19 with the Tohatsu 40 (that's who makes Nissan) for 11 yrs. and it still runs like a charm. Starts first time and purrs like a kitten with no water separator. I'm sure the fuel on the East coast is just as good or bad as our fuel out here on the Best coast. . Me thinks your service guy is trying to make an easy buck
Doug

[Paul S]

Captainjohn
I've had my Mac 19 with the Tohatsu 40 (that's who makes Nissan) for 11 yrs. and it still runs like a charm. Starts first time and purrs like a kitten with no water separator. I'm sure the fuel on the East coast is just as good or bad as our fuel out here on the Best coast. . Me thinks your service guy is trying to make an easy buck
Doug

He must have a few on the shelf he wants to get rid of

[captainjohn]

Well, upon further investigation, my dealer is doing me a big favor by installing the water separator filter. Virtually all gas in the US is now E10 with 10% ethanol, which can be murder on outboards. If the tank isn't used up within a few weeks, the alchohol combines with water and creates all sorts of problems. It is also a strong solvent and dissolves all of the old deposits in the engine which clogs the fuel system. You can google this at a number of sites. Even worse, some dealers are pumping gas with higher than 10% ethanol to save bucks, which can destroy an engine.

[Paul S]

I think there is potential for problems, but I have not seen any issue yet with the gas, even stitting for months. I just throw some STABIL in the tank and hope for the best.

I am sure there are some issues, I just havent seen it

Since ethanol is pricey I cant imagine a station putting a higher concentration in..I would assume it would cost him more $$

[Catigale]

I missed this post. A water separator isnt going to help remove water from E10 gas - the ethanol and water will meld into the fuel (exactly what dry gas or methanol does.)

[Night Sailor]

Hmmm. My '97 Merc 2 stroke has run fine for 10 years with no separator, but up until recently it didn't have ethanol in the gas. Now you can't find regular gas in my area. My Mercury Owner's Manual says that a fuel water filter is necessary if gas with alcohol is used because of possible water accumulation in the tank due to absorption of moisture from the air. I was considering getting one, but my Merc mechanic said it's not a problem with 5 or 10% ethanol polluted fuel, if you keep the tank full so there is little air to aborb moisture. I've followed this advice all the while I've owned it and the Merc has cranked right up with fuel that was over a year old but which had Stabil or a similar product in it. And I run the engine at least once per month for at least five minutes at 2000 rpm to keep fresh fuel in the carbs, even when on the trailer in the backyard. With full tanks, and frequent running, I consider it always ready to go for those occasional New Years days when it's sunny and in the 70s here in N. TX.

[Catigale]

That manual note doesnt really make sense. If the E10 gas absorbs water it will be carried by the ethanol in the solution and not separate in the separator anyway.

My 2003 Mercury BF has a separator under the cowling that comes with the engine btw. Ive never found more than a drop or two of water in the bottom of it, even after those big temp swings we get in the Spring and Fall season in upstate NY.

Its is EFI, which is more forgiving for small amounts of water in the gas of course.