Dirty Gas

[ccriders]

I made the mistake of running out of gas, and then after adding fuel, the engine faltered, would only run with choke out and/or at idle. Any power, even in neutral caused the engine to stall. I have a 1976 Pearson 28 with an Atomic four. When I purchased the boat two years ago I replaced the gas tank with a Tempo plastic 16 gallon tank, put in new gas lines, primary filter, fuel pump and in-line 2 micron secondary filter, and overhauled the carb.
I believe the Marpac primary filter is a source of most of the crud in the fuel. The filter is only 9 month old, but when I took it off the bracket the top inside metal structure was badly corroded and when I dumped the contents of the filter into a bucket there was a lot of brown stuf as well as some "gritty" substance. I took off the in-line filter, blew it out backwards and got more crud. Then I took off the carb and got more crud. Doesn't appear to be much water and the little there might be was in the primary filter. I don't need to use the engine very much, normally just to get out of the slip and down the fairway and around the pier, only a few 100 or so yards. I've put more time on the engine in the slip than underway just to make sure it gets run under load every week. I used less that a tank of gas in the last year.
Is there a better primary filter that won't introduce rust into the system?
Since I do not use more that a tank of gas a year, should I add a couple of gallons a month and keep the tank full, or run the tank to almost empty and then fill up? The old gas/condensation issue.
I have replaced both filters and cleaned out the carb and the engine runs very nicely, so the problem was clearly contaminated fuel.
Thanks for your suggestions. It would be nice to have a regimine that assures clean fuel all the time.
John

[sailingdog]

Sounds like you got crud into the carb and clogged at least one of the jets.

Get a Racor primary filter. They will get rid of the crud and the water. If the gasoline is an ethanol blend, you should really add a stabilizer to it every time you add gasoline.

You'll really want a fuel/water separator-type filter, since, if an ethanol blend gasoline absorbs more than 1.5% of its volume in water, the ethanol can separate out and cause serious problems. Ethanol is used as one of the primary octane boosters in ethanol blend gasolines, and if it separates out, the gasoline is only about 82 octane, rather than 87 or higher, which can also cause problems with the engine running properly.

The Racor will look something like this:



About $50 or so.

[sanjuan2R]

I also have an Atomic 4 engine with a generic primary filter. How good is a Racor primary filter? Ethanol blend gasoline is all they sell now in Oregon. How will a gas stabilizer help the situation? I am still learning about my A-4 engine and it's quirkiness. Any help in keeping this A-4 ruinning well?

Thanks.

[sailingdog]

Some of the newer fuel stabilizers help prevent the ethanol from separating out and such. Most will also help prevent the gasoline from forming gums and varnishes, which can clog carburetor jets and such.

[SEMIJim]

ccriders, sanjuan2R,

While Sailnet is a great resource for many things, your best resource for all things relating to the Atomic 4 engine is Moyer Marine and the Moyer Marine Atomic 4 Forums.

SD,

Those Racor fuel filters and fuel/water separators are all plastic, no? A while ago I thought I read U/L or ABYC or somebody disallow plastic fuel system components in inboard engine installations. Can't find anything on it now.

Jim

[ccriders]

Originally Posted by SEMIJim

ccriders, sanjuan2R,

While Sailnet is a great resource for many things, your best resource for all things relating to the Atomic 4 engine is Moyer Marine and the Moyer Marine Atomic 4 Forums.

SD,

Those Racor fuel filters and fuel/water separators are all plastic, no? A while ago I thought I read U/L or ABYC or somebody disallow plastic fuel system components in inboard engine installations. Can't find anything on it now.

Jim

I agree. I have their overhaul manual and have printed out many of their FAQs for trouble shooting purposes. Their writing is very clear and concise. But this was not an atomic 4 problem, but a concern over the fact that it appears the primary filter itself is the source of crud in the system and a question of whether I should keep the tank full adding a couple of gallons a month or to run it down to a couple a gallons and fill up.
I hope plastics are not disallowed for inboard fuel systems as that would mean a new gas tank and fuel lines. Thanks for your response.
John

[SEMIJim]

Originally Posted by ccriders

... whether I should keep the tank full adding a couple of gallons a month or to run it down to a couple a gallons and fill up.

You'll probably get as many opinions as there are sailors . I tend to add a couple gallons, via a small gas can, whenever the tank drops below about half or so. We have a 20 ga. tank and we have to motor up to 45 minutes, each way, to/from our slip. For winter storage I top it off. I add Stabil to our fuel.

Originally Posted by ccriders

I hope plastics are not disallowed for inboard fuel systems as that would mean a new gas tank and fuel lines.

Not sure. Thot I read it somewhere, last season, when I was researching our fuel/water separator/filter (about which I can find nothing, atm, either!). Maybe I imagined it all.

Jim

[sailingdog]

SemiJim-

Some of the filters are metal and glass... others are all plastic... I seriously doubt that RACOR, which is one of the bigger manufacturers of fuel filters would be selling ones that weren't safe to use for their intended purposes.

[hellosailor]

Year old fuel will have gone bad. Gasoline is a witches' brew of about 60 ingredients and fractions, including some like butane and heptane that literally boil off at room temperature and are gone with 90 days. Which is all the life that "pump gas" is intended for.

So if you use it that slowly, add stabilant every time you fill up, that is designed to compensate for the stuff that evaporates out, and to prevent other parts from turning into varnish--which also forms naturally in gasoline as it ages. Keeping water in solution is only one more part of the challenge.[g]

Racor is probably "THE" brand name, but IIRC the filters with transparent glass bowls are often used incorrectly--there are regulations about what can be used on boats, and the regs and traditions often don't quite match, it would pay to check.

I like a semi-permanent sintered brass/bronze filter in the fuel line right before the engine (Ford used to design these into some of their carburetor fuel inlets) because it isn't the finest filter, it isn't the cheapest filter, but it is porous metal and unlike paper or cloth, it can't be "torn" in some way that lets crud get past it.

But even with the best of gas, best of care, gas tank kept filled and water from the deck kept out...gasoline just needs help (additives) if you want to use the same gas more than 90 days from purchase date. Six months if you're lucky.

[SailorT]

I recently replaced my Racor fuel filter/separator and while researching the different models I read that ones with metal bowls are required for inboard engines because the heat from the engine could melt the plastic bowls, like the one in the pic which sailingdog posted above.