Moderated Discussion Areas
  ContinuousWave: Post-Classic Whalers
  Water separator for Montauk 170 (2005)

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Water separator for Montauk 170 (2005)
pvonk posted 07-29-2006 05:00 PM ET (US)   Profile for pvonk   Send Email to pvonk  
I've spent about three hours combing through posts to learn more about fuel-water separators. I now know where to put one, possible need for one (even for external OEM tanks) given the ethanol issues, etc. However I came across one question that was not answered - something like "check to be sure you should add a separator given your type of engine (there may not be enough pull to get gas to the engine with an extra filter added)."

I have a 90 4-stroke Merc (not efi) and am using the two plastic tanks that came with the boat, have original fuel line and primer bulb (currently about 80 hrs total). Is there a pressure problem if I add one (I just bought a Sierra at West Marine, but can return it)?

- Pierre

Speedo66 posted 07-29-2006 05:37 PM ET (US)     Profile for Speedo66  Send Email to Speedo66     
I put one on my 2004 Mercury 60 HP 4-stroke, and it works fine. For the record, this is a fuel injected model.

I also found the poor man's (cheap b@st@rds) way of getting a 10 micron Racor fuel/water separator filter at a more reasonable price. They make a spin-on metal filter element, PFF5510, that is designed to fit most other housings. It runs $8-10 depending upon whom you buy it from.


Mambo Minnow posted 07-29-2006 08:53 PM ET (US)     Profile for Mambo Minnow    
Our family MA dealer just installed a racor water/fuel separator on our Classic Montauk with Evinrude 90 HP 2 stroke due the E10 introduction. It was mounted on the forward part of the transom well, dead center. They added a clear plastic fuel filter so we can perform a visual check for water in the line. This was an upgrade from the standard metal filter.
davej14 posted 07-29-2006 09:36 PM ET (US)     Profile for davej14  Send Email to davej14     

Can you provide more info on the clear plastic filter? Brand, P/N etc?

bigjohn1 posted 07-30-2006 08:15 AM ET (US)     Profile for bigjohn1  Send Email to bigjohn1     
No problem at all...I personally know three boat owners with your very same engine and all have installed external water separating filters. None have had any problems with fuel starvation.
divefan posted 07-31-2006 01:16 PM ET (US)     Profile for divefan  Send Email to divefan     
Hi guys,

I have a question regarding this thread. This is not meant as a criticism of anything that has been said. I am just curious.

Why would you need a fuel/water separator when using the standard 6 gallon outboard plastic tanks? I have these as well and I use them with my 90 HP 4-stroke. I fill them at the gas pump where I fill up my truck. I add an ounce of the 2 additives recommended to keep the carbs clean and a drop of stabilizer just in case I leave the boat idle for a week or more. I have never had problems with water in my gas filling at the local gas station. I understand the need if you have large inboard tanks gas or diesel but in the small 6 gallon ones I don't get it. Thanks.

bsmotril posted 07-31-2006 03:20 PM ET (US)     Profile for bsmotril  Send Email to bsmotril     
It's a belt and suspenders kind of thing. And now with the advent of more ethanol in gasoline, it's like your walking around with a couple 4 oz sinkers in each pocket. BillS
Speedo66 posted 07-31-2006 04:00 PM ET (US)     Profile for Speedo66  Send Email to Speedo66     
With the advent of ethenol in gas it's a good idea. Alcohol tends to absorb water from the atmosphere, and will pull it into your gas.

If you ever bought grain alcohol as a kid to make you own concoctions, you probably noticed it pegged at 190 proof, not 200, even though it's "pure" alcohol. That missing 10 proof is the absorbed water.


davej14 posted 07-31-2006 04:39 PM ET (US)     Profile for davej14  Send Email to davej14     
I have asked this before without any response. Since water mixes with alcohol, how does a filter trap it? Uness there is so much water that it cannot be held by the ethanol, it would just be transported to the engine and burned. If the fuel supply is contaminated with large amounts of water then I see how it could help, but water separation should be less likely with ethanol blends.

I still think that an external filter is a good idea (I have one), for trapping water, debris and gunk that the ethanol may dislodge. I don't see how it will help remove water content that is mixed with the ethanol. What am I missing?

bigjohn1 posted 08-01-2006 01:57 AM ET (US)     Profile for bigjohn1  Send Email to bigjohn1     
Divefan, I pondered your same question for quite a while after buying my 170 - I think I even used some of your insight in deciding to buy the boat in 2004. Like you, the primary use of my boat was meant to be for spearfishing the reefs around the island. After a while, I came to the conclusion that my non-family-friendly sport had to be shelfed for a few years due to our young children. So, we switched gears and I started trolling with the boys. For the longest time, I felt it useless to add the additional rigging clutter of a separator given the use of the puny stock tanks and doing most boating very close to shore.

Now that I venture much further offshore and my larger tanks get lots of water spray (not to mention the ethanol issuses), I decided to add one and am happy I did. If nothing else, its fairly cheap insurance for my 115EFI that I'm sure would not take too kindly to water ingestion. I guess I just don't trust that little red slider tab inside the cowel filter.

With all of that being said, if I were still just reef hopping with the little 6 gallon tanks, I might have thought differently.

bigjohn1 posted 08-01-2006 02:01 AM ET (US)     Profile for bigjohn1  Send Email to bigjohn1     
This thought just hit me.....does anyone know what the micron value is for the stock Merc under-cowel filter? Given that some/many have had problems with gummed up carbs on the Mercury 90 4-stroke, perhaps a 10 micron filter is even a better idea for those with this engine. Divefan, you may have just answered your own question??
divefan posted 08-01-2006 05:44 PM ET (US)     Profile for divefan  Send Email to divefan     

I guess that's it. I don't go too far where I live. We have 100' at 1 mile offshore. 3 reef lines to choose from in between. So I get all the action underwater I can handle with my two little 6 gallon tanks. In fact, with the 4-stroke I can hardly use one whole tank after a whole day out on the water. 3-4 divers full gear 2 steel tanks each and plenty of refreshments. :-)

I was curious is all. Btw, I have been using the carb cleaner and quickkleen as well as a stabilizer in every tank full just as a precaution since the last issues came up with the carbs. Everything has been fine since then. :-)

Anyway, was out this morning and bagged a whole cooler full of hogfish (a wrasse that people call a snapper). Very good eating. So I need to get going. Fresh fish for dinner! :-)

Man I would love to see what you have to kill out your way. Must be great!

Thank you all for your responses to my curiosity.

Barney posted 08-01-2006 07:40 PM ET (US)     Profile for Barney  Send Email to Barney     
I'm using a 10 micron filter, 89 octane and Quickleen. After sitting for about 3 weeks the 90HP 4-stroke took about 15 minutes for the carbs to clear out while underway. Idles fine, although I've got the idle turned up. I started it a couple of times under earmuffs during that period too. At least it clears, at least it will start and run well after a while. Maybe leftover gunk coming loose from my abusing it after Katrina, maybe something else. I just want another 3 years out of this outboard. Jim
Mambo Minnow posted 08-02-2006 08:55 PM ET (US)     Profile for Mambo Minnow

PVONK - invoice read Mercury water separator kit and Racor fuel filter. No part no.s sorry. The filter looked like those in attached link, with the sight glass on bottom and a gravity drain plug on bottom.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.