Inline Fuel Filter?

[Cofe]

I was wondering if it was kosher to install an inline filter from my 2cycle tank to the motor? Will the mixed fuel be a problem for the filter? Also I noted that I can see an airspace in the transparent filter, will this cause problems? Any info appreciated..

 

[nymack66]

Re: Inline Fuel Filter?

Just make sure its rated for pre-mix and will normally be on the package ..

 

[Chris1956]

Re: Inline Fuel Filter?

Although it is possible to filter out the oil from a premix, it would take a very expensive, very fine filter to do so. You will not find a filter of this type in the boat shops, since they are a specialty item.

Make sure the inline filter is rated for the HP of the motor. I like to use the 3/8" models for the higher HP motors(75HP+). 5/16" is good for the smaller motors.

 

[Cofe]

Re: Inline Fuel Filter?

Thanks this info is helpful.

 

[fishrdan]

Re: Inline Fuel Filter?

I'd be more inclined to install a small filter inside the outboard, if there wasn't one there all ready. It would catch any of the dirt and debris that build up on the quick disconnect fittings.

 

[Cofe]

Re: Inline Fuel Filter?

I'd be more inclined to install a small filter inside the outboard, if there wasn't one there all ready. It would catch any of the dirt and debris that build up on the quick disconnect fittings.

Thanks for the tip

 

[techwriter]

Re: Inline Fuel Filter?

You did not say why you wanted to install the filter. Maybe it is just to help protect the fuel system.

A standard type of in line filter that is paper or more precisely cellulose should work fine for what you want to do. Cellulose is not suppose to be used with oil as the flow would be greatly restricted. At a 24:1 or greater mix the oil is thinned enough for the filter media to function properly. My Evinrude 110 HP has a factory installed inline paper filter under the engine cover so that would be the same difference.

If you have a problem with contamination in your fuel and if you have an inline filter within your engine cover (I am not familiar with your Mercury). Then you may want a prefilter in the line where you are talking about putting this. Assuming that you are using a 3/8" I.D. fuel hose on that size engine. A NAPA part number 3270 or Wix 33270 filter would do a good job as a prefilter only, not as the secondary filter. Any automotive parts store could cross it from those numbers.

This 3270 is a metal filter housing with a 120 mesh screen instead of the paper or cellulose filter that would be about 20 micron. It has a hose barb on each end to slip into a 3/8" hose. To my knowledge it is the only inline filter available with a screen in it and 3/8" is the only size that it comes in. I have researched that looking for it in a different connector size.

This filter is actually designed for a use as a prefilter on a smaller Cummins diesel engine. Some of the aftermarket parts stores computer systems and catalogs will show it as a nylon filter with the two connectors on the side. That is incorrect information. It is as I described above.

Whichever you decide to use should make no difference as to the kind of fuel or fuel oil mix that you use with it. If it is a plastic housed filter it may not be resistant to gasoline with ethanol in it. Most after market fuel system parts that are not intended for use with alcohol are listed as such on the package or the instructions.

If you are wanting to install this as a good measure to prevent a problem it is not a bad idea. If you have a contamination problem that is in the tank you should look into taking care of that.

One other thing to mention about this is that even though most people may not realize it. New oil will go bad in the container. I have seen oil that had set on the shelf a long time before it was sold to the end user. It looked OK and was mixed with fresh gasoline. Once mixed the fuel/oil mixture contained grains of varnish from the old oil that immediately plugged the carburetor. My point is that any gas or oil that is old and beginning to varnish will plug any screen or filter very quickly.

Oil that my company buys for one marine engine manufacturer is oil that has set on the self a long time before they ship it to us. We send about 700 gallons of new oil a year to be recycled on some years because it has gone bad and should not be put in a customers engine. I should add that the engine manufacturer that I am referring to does not make 2 cycle or outboard engines and most engines are larger than 500 HP.

There is a difference in filters. The cheaper filters will have about 30 - 40% less filter surface area than the better quality filters have. The cheaper filters are often just paper where a higher quality cellulose and even glass fiber is used in the better filters. Many suppliers and parts stores have at least two qualities of about everything that they sell. They have the cheap line for direct over the counter sales and they have the professional line that goes to the repair shops and manufacturers. One suppliers cheap over the counter filter line is called the "Pro" line of filters. If you ask they do not mind selling anyone the better quality that will normally cost more.

Air should not be a problem with a carbureted engine.

 

[Cofe]

Re: Inline Fuel Filter?

Thanks Tech. I didn't realize that 2cycle oil would go bad. The info is appreciated.

 

[AUGIDAWG]

Re: Inline Fuel Filter?

How about a "Mr. Gasket Co." part number 9746?
Is this one compatable with oil/gas mixture?

 

[wilde1j]

Re: Inline Fuel Filter?

If you're going to bother with a filter, why not use a Racor or similar 10 micron water separating filter, especially if you're using fuel with ethanol. You can get a Merc or Racor for under $20 and not have to worry about water getting into the carbs. BTW, 2 cycle oil does not go bad, or I've never seen it and my Dad had a marine business for many years and often we bought oil 3 to 5 years before selling all of it and never a complaint. Also, don't worry about any decent marine filter stopping oil from premix ... it just ain't gonna happen.