Fuel Filters and Injector Cleaners

[Ranman]

Can anyone here tell me how well your basic Merc water seperating fuel filter handles particles? I realize these things seperate water out of your fuel, but what about crap in the fuel? Will these filters allow particulates to pass through to my fuel injectors??

Also, does anyone know anything about fuel injector cleaners? You know, the stuff you pour int the gas tank? Do they do ANYTHING?

The reason I ask is because at this point I still feel that my boating woes to date have been caused by either bad gas, water in the gas, crap in the gas tank or a combination of these. It seems that every time I replace the Merc W/S fuel filter, the boat runs better for a bit, but then degrades. I've finally drained the last of the fuel in the tank. I've been on this same tank of gas ever since the trouble started. I'm going to get fresh gas and I've replaced the filter again. The last two filters that have come off the boat (both with 5 or less hours run time) had a small amount of water in them along with some solid particles. The first filter had more solids than the second and the second has more water than the first. Now I'm wondering if I could have contaminated injectors??? Any thoughts???

[BillG]

How about some water remover in the tank? Just make sure it only contains isopropyl alcohol as that is the only kind that will mix with water. It is the same thing that is in rubbing alcohol, which is usually 70 percent alcohol and the rest is water. The other kinds sit in the tank and attract water but do not mix, so you have a mess in the bottom of the tank.
Bill G

[Ranman]

I did pour two bottles of the isopropyl stuff (dry gas) in the suspect tank (30+ gals of fuel). I've heard this isn't the greatest stuff to use, but it was too late. The performance of the boat improved somewhat after that, but again degraded with a little running time. The tank that had the dry gas has now been drained and is currently empty. I'm thinking of trying to bring a small 5 gal tank of fresh gas with me in addition to a fresh 40 gals in the tank. If the boat starts to run rough, I would change the filter and switch to the 5 gal portable tank to see if it makes any difference. I just don't know how the hell I'll strap down a portable tank in the cockpit to go for a run. Prolly not the safest thing to do, but I have no other ideas???

[MOP]

Randy one word RACOR! Can't beat them, Merc filters do the gravity thing to drop the water. Racor swirls the fuel does a far better job.

[mikev]

go to walmart and get some berrymans b-12 carb and fuel injector cleaner and dump it in the tank i have a 30 gal tank and dump in 2 cans. this stuff works wonders i use it in the truck two.

[MR.MAGIC]

GO WITH A RACOR,YOU CAN USE A MERC MOUNT, CUT YOUR OLD MERC FILTER OPEN AND YOU WILL SEE THAT THE FILTER IS SMALL,ALLSO YOU CAN DRAIN THE WATER FROM THE RACOR WITHOUT TAKING THE FILTER OFF.

[MOP]

I had an injector problem with my truck I went back and forth with Jim (BUIZILLA) He spoke I listened now truck runs fine. Jim recommended using STP *concentrated or Chevron Techroline every third tank, I been using the STP 4 pack from the discount house of worship.

Thanks again JIM!

[BUIZILLA]

Randy, you NEED to get your tank drained completely, and spotless clean, THEN use the additive(s) that I Told MOP to use. Just adding dry gas, doesn't rid the fuel cell of trash. It just breaks down the water into smaller molecules, to allow it to *flow*, and the engine to digest it. Dry gas does NOT breal down solids.. The factory M-cruiser filter does NOT have small enough micron rating, it's just a *general service* filter. Anything over 10 micron in a diesel or EFI application is suspect for trouble. I prefer 5 micron, but that's just my opinion. Most filters are 30 micron. The industry has no minimum standard.

The 220 Racor series does a good job, easily serviced, trap drain, and different micron elements are available. Since the 220 can be used on small diesel applications, study the catalog carefully for the CORRECT GASOLINE element selection.

Mount the Racor in a vacuum scenario. NEVER pressurize a water seperator, or it will NOT work. If your Merc filter is AFTER the electric fuel pump, that is 99% of your problem. Once the bottom of the water portion of the filter fills up, it pumps water continuosly into the engine. if it's before the fuel pump, it'll still suck the overlaod water. Gas EFI injectors hate water...

I am convinced the factory M-cruiser filter is responsible for most all of these 454-502 power problems. I flow a LOT of marine gas injectors here on my sophisticated test stands, up to 10,000 rpm and 18ms, and I have seen a ton of problems.

Unless you drain and hand wipe the tank, you may continue top have problems. By and large, 99% of marine tank pickups do NOT touch the bottom, they stay suffiently off the bottom, so that water and dirt can never be eliminated, unless it is manually wiped or sumped.

I would NOT use a Racor and factory M-cruiser filter in tandem. Get rid of the factory unit. The stock fuel pump is kinda weak on the vacuum side, and restriction is your enemy pulling thru both filter media's and the mickey mouse anti-siphon valve.

J