Racor Filter Selection

[Rob & Karen]

I am considering adding a Racor filter to my fuel system. I have a 115hp mercury engine. I have searched the Racor web site, but I am having trouble figuring out exactly which filter I need. There seems to be different sizes and different micron level filters for outboard use. Could someone give a quick rundown on Racor filters? Thanks.

Rob

[thataway]

You want a gasoline rated spin on filter. The place where it gets a little tricky is that the clear bowl (water separator--which can be drained) should only be installed outside a bilge area. C Dory has put some of these clear bowl filters in boats with cockpits, or bilges--ie the CD 25 and the Tom Cats. If you put the clear bowl filter in the splash well, then it will correspond to ABYC standards, if the metal bowl is installed in the inner part of the boat, it will meet ABYC standards.

I generally run 10 micron filters on the gas engines. On diesels I tend to run a 30 first, then a 10 and finally a 3 on the engine itself, if the system so requires.

[Almas Only]

Per Racor technical representative, and Racor product literature, you can substitute their diesel replacement cartridges for gas versions. There are only two differences: diesel has more antifungals, and generally go to smaller micron ratings.

You can go around and around on spin-on filter size, but I use a fairly simple approach: I want the smallest micron rating possible which still allows enough gasoline to pass so that the motor runs on WOT, and will go a season without the filter needing to be replaced. Anything bigger merely allows more crud to head toward the secondary filter, and carbs, merely so that I can have a fuel flow rate through the primary filter significantly higher than anything the motor can possibly burn.

I use the Racor 2 micron diesel (R12S, West Marine #411355), have never had to change the cartridge mid-season, and am always able to go sustained WOT long enough to assure that there is no flow reduction at the filter which affects motor performance.

The used filter elements, when torn down to component parts, always appear to be in good shape, with a slight discoloration band at the botton, approximately 1/4 to 3/8 inch high, which I interpret as indicating that the filter has lots of unused capacity.

The Honda filter under the motor cover was changed out and torn down at 950 hours use, and, not surprisingly, showed no accumulated debris or evidence of cloging. The carbs were torn down, and they too were clear as could be.

I don't know if the 2 micron version is adequate for a 115 hp motor and the fuel quality you will encounter, but 115 is close enough to 90 that I'd be tempted to use the 2 micron, and if there were any indication that the motor was fuel starved, then to to the 10 micron. Racor rates the diesel filters at 15 gph (diesel), so I assume they pass more gasoline. But, the real question of the end-of-season flow rate can only be answered by field trial.

[C-WEED]

Rob,

Here is a link to the basic setup.

http://www.marinefilters.com/productdetails.php?number1=5&modelnumber=W320RRAC01

This is a 10 micron filter. Once you get the three part setup you can change filter micron size at any time. The three parts are the mounting base with two inlets, one outlet (For two tanks) the filter, and the fuel bowl.

There are some filters available without the drainable bowl at the bottom. I would not recommend these. The ability to drain and inspect the sediment/water/fuel is what makes these drain bowl types desirable. I have only refueled at one marina and wound up with way too much crud. Even when shuffling fuel in clean portable cans from gas station to the boat I am still amazed at the debris and water I get from the drain bowl.


Something else to consider. As Bob mentioned the filter should not be bilge mounted without the metal fuel bowl. I assume this is due to possible damage from being hit as in my boat or heat damage if mounted in an inboard installation.

I bought my boat used and it has the plastic bowl (which is quite durable) on the filter. The two different mounting locations that most filters are mounted on the CD-22 are down between the fuel tanks or up in the splash well mounted port or starboard, opposite of a swim step if you have one. My filter is mounted low just to the right of the port fuel tank. Just to the right of the filter is a bilge pump. When I bought the boat I thought, this is a better location as in out of sight, and with two big dogs always jumping in and out over the swim step = less chance of damage.

A few weeks back we had the boat out for a weekend camping trip. First outing of the spring. The bilge pump had run a few times to evac some water the dogs drug in. Anchored in a quite cove my wife points out a slight sheen of oil on the water behind the outboard. I dismissed it as a drip from the exhaust or engine cowling from the tipped up outboard.

On the return to the launch point about 8 miles away we are put-putting along on the kicker. I get a wiff of raw gas and kill the engine to investigate. I had to move some camping gear just to get at the bilge/filter area. I was shocked to find the filter dripping fuel. And a nice puddle around the bilge pump. I would rather deal with a sinking boat than have fuel dripping on the floor.

I killed all the electrics except the motor. I was trying to keep that bilge from kicking on. I later remembered it was hard wired to the battery... I sponged up all the fluid into a 5 gal bucket. Had the extinguisher ready. I decided that if it went poof I would just try to get away from it. (Extinguisher not much use) Put the wife in life jacket, put her and the dogs up front and had the front hatch open for escape and closed the cabin door. I drained the fuel bowl into a small container and found some maple sirup looking crud. The filter normally can only leak from one of the two seals. The one above the white filter and the o-ring above the bowl. As near as I could tell it was the o-ring leaking. I had an extra filter but wasn't inclined to change it out there as it would have resulted in more spilled fuel. When I did change it at the house it required the rubber strap wrench so I wouldn't have been able to change it anyway. I ended up wrapping the bowl with several layers of duct tape. This stopped the drip considerable. I had a small container that would fit under the filter to monitor the leak and drain as necessary into the five gal bucket. I switched to the main engine and the plan was to make a dash to the ramp. At warp drive I should be there in no time. Wrong again. I wasn't sure if the filter was clogged or drawing air thru the leaking seal. The main engine would not run above 2000 rpm. Long story short after a long tense cruise to the dock we made it. When I changed the filter the o-ring looked fine. I don't know if the failure was caused by fuel additives, ethanol which has just arrived in our area or a clogged filter pulling enough vacumee to make the seal leak? I would recommend that anyone with a filter in the bilge location carry a container that will fit under the filter in this situation. A container that will hold enough fuel can be hard to find as the filter base is close to the floor not allowing much room for the container to fit around the filter.

I remember reading another brat had a similar failure awhile back. The whole point to this story is I now realize that the mounting of the filter in the splashwell is a much better location. It is easier to service. If you have a leak it goes out the well drain. You can use the washdown or a bucket to flush if needed. I was going to flush the floor with water and pull the drain plug once I got up to speed. But when I couldn't get up to speed that idea vanished. Hope all this rambling helps...

Since I don't have any marine places close by I have to buy off the web. Needing a few racor replacement filters I stopped by a local car quest auto parts. I gave them the racor number and they said they could have them the next day. I looked at the computer and saw three prices List $65, our price $21 and sell price $36. I kindly told the guy I could get them cheaper on line. He asked with shipping I said yea, If I buy over $50 shipping is free. He said: How much? I said $25. He didn't hesitate a second to type in the sell price to $25 to make the sale. I bought two fuel filters and two outboard oil filters for $10 each. We were both happy!

[thataway]

2 micron is correct--sorry about the mind lapse and 3 micron filters (must be all of those "looney's" around here.

Not sure about using diesel filters in gasonline, but definately gas filters will not work properly in diesel. I once had an RV where a mechanic mistakenly put in a gas filter on a diesel Racor filter, and it plugged up the line in about 100 miles.

The rules are not entirely clear, but many interput the plastic bowl as being not allowed in gas engine compartments. The way it is written it would imply that any use below deck is not acceptable--or where there is an access to the bilge, such as in the CD 25 (My CD 25 and Tom cat both came from the factory with the clear bowls, and I have left them.

[flapbreaker]

You might take a look at this website.

http://www.aaaa-generator.com/RACOR_R12T.html

The R12T was the direct racor replacement for the Honda branded one. This was confirmed by DaNag via Racor.

[Almas Only]

The R12T is a 10 micron element; the 2 micron is the R12S. They are both Racor 120 Series, and interchangable, depending on your desired filtration level.