Water/Fuel filter and separator

[PEN24]

I've just had a new Yamaha 70 installed on my speedboat and the dealer insisted that "as it's a 4 stroke" you need a fuel/water filter separator in the fuel line. I have been using my with a Yamaha 50 4 stroke for years without one so is this really necessary?

[Bobglas]

If its similar to my Yamaha 60 (3 yrs old) there is a fuel/water filter on the engine. I had a water in the fuel problem last year. At 8 -10 knots the engine would die. You can see the water in the filter as the housing is clear. I unscrewed it and poured off the water. Ran fine for a short while but happened again. Repeated the operation but alas there was more water in the fuel. I was able however to run at 5 knots w/ out the water being sucked in. Made it 10 miles to my destination.

[grady]

An extra water separator/filter will never hurt. Since these are not large tanks where when you stor them empty you can get condensation build up. Water issue is almost always from poor fuel handling practices or fuel tank seals. Ether from you or the Marina where you purchased the fuel.

[mallardjusted]

I've run 4-strokes for a dozen years and have tried to be careful with the fuel (no thanks to ethanol!). I also have a 2 year old Yamaha F70, and this spring had to be towed due to water in the internal water filter!!! I had an external water separator installed right after that. I also have a 2014 Yamaha 50 on my duckboat (same block as the F70), and had water/fuel issues a month ago, so I installed an external one on that myself. My recommendations would be to install one - the size of the filter is 10x bigger than the little one inside the outboard, and easy to get to .... and, it took me less than an hour to install for less than $90.

[Clipster]

For those of you who have installed external water separators, where did you mount them? I've wanted to install one on my X, but couldn't figure out the best way to do so. If you also have pictures that would be great.

[Nauti Nell]

PO had put one on my 26M in the aft of the port side fuel area with a cage built around it to keep fuel tank from hitting it. It will be a week before I get to the lake and can take a picture.

[Herschel]

For those of you who have installed external water separators, where did you mount them? I've wanted to install one on my X, but couldn't figure out the best way to do so. If you also have pictures that would be great.

Got pictures of just about everything on my boat at the ready (Photobucket), but not the fuel water separator/filter. I do have one on my 2011 Yamaha 50 four stroke. It is mounted on the bulkhead just aft of the starboard gas tank compartment. I keep my boat at a slip in Central Florida year round, so there is ample exposure to condensation build up with our heat and humidity. I make a point to keep my two 9 galleon tanks as full as reasonably convenient. I'll head to the fuel dock when just one goes down to 3-4 galleons. I do that to minimize the volume of humid air in my tanks. I make a point to run my engine at least as often as every three weeks at WOT for at least 15 minutes. I add Marine Stable and Yamaha fuel additive to each fill up. I check my external fuel filter every three months and get my 100 hour service for the engine on time. With that regimen, I have yet to find any water in my external fuel filter. My engine has performed flawlessly except for the first time I tried to check/change the external filter and did not get the seal set properly. I think that if I were not able to maintain this regimen, I would find water in the external filter. So, for me, it is an nice insurance "policy" for which I have not yet had to "file a claim".

[K9Kampers]

For those of you who have installed external water separators, where did you mount them? I've wanted to install one on my X, but couldn't figure out the best way to do so. If you also have pictures that would be great.

I mounted mine on the forward wall of the starboard side fuel locker. I chose that location for the accessibility to thru-bolt the mount, by removing the flotation foam thru the access hole in the aft berth ceiling. The size of my fuel tanks allow room for the filter and items I don't want to store below: (stove fuel, gear oil, propane cylinders...).

[ris]

We have traveled 3876 miles since 3 April 16 without any filters except what is on the motor. We have a 60 hp 2015 Honda. Checked the engine main filter and there is no water in it. If it ain't broke don't fix it.

[Herschel]

We have traveled 3876 miles since 3 April 16 without any filters except what is on the motor. We have a 60 hp 2015 Honda. Checked the engine main filter and there is no water in it. If it ain't broke don't fix it.

ris, with all those miles under your belt, you probably know much more about this than I do, but I was thinking that since you are going through your gasoline almost everyday, you would not have moisture building up in your tanks. It is the guys, like myself, who sometimes go a few weeks between running the engine that have to worry about the moisture condensation in the tanks, if they get too empty for too long a period of time and in high humidity environments. Am I wrong about this?

[ris]

I believe you are correct. The more time the fuel sits in your tank the more chance for condensation to take place. I have those new fuel tanks that do not vent until a psi threshold is exceeded, I wonder how this affects moisture build up in fuel tanks? These tanks expand a lot when they get hot.