the best fuel filter for gasoline engines

[naturewaterboy]

I am rebuilding a 34 Silverton and want to put some good fuel filters in for the twin outboards. What does anyone recommend? Water separators, what micron filter is good enough? I think my engines can drink 30 gallons/hr. at cruise, I am going to install two filters with crossover and shutoff valves to allow me to run both engines off of one filter if needed. I looked at Racor's website, but I didn't find any advice on their products. I'm not looking for cheap, I want the best I can get without buying more than I need. Any recommendations are appreciated!

[gonzo]

For gas you can install the spinon filters. They look like an oil filter canister. The holder is probably $65.00 and the filters $8.00. Several companies make them

[mydauphin]

The spin on are ok, but I like ones with plastic bowl with water removing dohicky...

[apex1]

Go with the Racors, a semi pro quality, hard to conquer. First Filter element 10 micron, second 3 micron. Have the version with the plastic bowl / separator as "motor barge dauphin" mentioned.

Regards
Richard

[FAST FRED]

The best thing you can do for your filters and engine is to gasolene with out alcohol dumped in.

It dissolves GRP tanks , eats old hose , and carb gaskets and goes foul in about a month.

Alky doped fuel will absorb water fromthe air constantly , and engines dont run on water.

The new method of handeling gov required poor fuel is to leave the tank as empty as you can (backwards from the past 75 years) , fill only what you will use on a run , and come back as empty as you dare.

Pump what "gas" is left in the tank, and dispose of it thru your car.

FF

[mydauphin]

Ture Fast Fred but in Florida for example, you can't gas with alcohol in it.

[FAST FRED]

All the Gas we find in FL has 10% ethanol dumped in.

The only place I can find unaltered gas is the local airport.

Costs a bit more but outboards,gensets , lawn mowers and other items do not need to be serviced after every use .

FF

[TollyWally]

Damn I wish that was practical. I'm going to run my tanks down as far as I dare and try and figure out some way to pump the bottom of the tanks out. Any idea what to do next? My tanks are built in and replacement is out of the question at the moment.

[mydauphin]

Fred can you buy avgas at the airport in your trailered boat?

[FAST FRED]

You can buy gas at the local FBO with money or a credit card.

We use AV Gas in our motorhome gen sets (haven't changed to propane yet), and simply pull up to the av gas truck.Not Cheap, but far easier than hasseling with dumping old gas.

FF

[apex1]

Damn I wish that was practical. I'm going to run my tanks down as far as I dare and try and figure out some way to pump the bottom of the tanks out. Any idea what to do next? My tanks are built in and replacement is out of the question at the moment.

Buy a good additive.

[naturewaterboy]

Well, I've emailed Parker/Racor, and a young guy there told me the best filters I can use are the Racor Turbine series filter, 500MAM2. This has a 2 micron filter element, clear (or metal also available) water bowl. A couple of distributors/retail sales guys say to use the 320R-RAC-01 Racor filter systems - they are only 10 micron filters, and have the metal spin on filters. Seems like 2 micron is a lot better than 10 micron to me, even though the 500MAM2's cost about $270 each and the 320R's cost about $70 each. I'd rather put $400 more into filters if it may save me from engine damage. Would I be throwing away money - does it matter to a 2007 Mercury Optimax if the filters are 2 or 10 micron? Is one filter better than the other at keeping water out of the engines?

[apex1]

If you install the 10my element the particles passing are to coarse for a long engine life. And they can (and will) clog injectors, tubes, hoses etc. If you install the 2my element it will be clogged soon by these large particles. I always recommend to install a cheap prefilter (cheap replacement) of about 10 - 12 my AND a better one of 2-3 my. The latter does´nt need to be replaced too often in that case. Ask your dealer for the newest series of filters when you buy the clear bowl (recommended), the older ones did crack after contact with alcohol (ethyl).

[FAST FRED]

If your engine is fitted with carbs , the 10micron is as clean as you need to go.

The holes and passages in carbs are huge compared to what is needed for injection .

The old style bronze filters as a pre filter work well, and are cleanable , remove gunk and water , with NO replacement parts needed.

FF

[apex1]

If your engine is fitted with carbs , the 10micron is as clean as you need to go.
The holes and passages in carbs are huge compared to what is needed for injection .
The old style bronze filters as a pre filter work well, and are cleanable , remove gunk and water , with NO replacement parts needed.FF

Thats right.

[Jimbo1490]

ALL gasoline intended for use in automobiles in the US MUST contain 10% ethanol, including here in FL. But the marinas succeeded in getting an exemption from this requirement, so you can get ethanol-free gas, including the *original* Amoco ultimate at your local marinas.

100LL runs fine in 4-stroke engines, but is no good for 2-strokes. Remember that while the 'LL' in 100LL (http://www.sportys.com/terryc/images/1999m.jpg) (blue) stands for 'Low Lead', this 'low' is only in comparison to the older '100' (http://www.aircraftspruce.com/catalog/graphics/09-42808.jpg) (green) grade of avgas. 100LL actually contains an enormous amount of lead (as TEL) at 2 grams/gallon, about twice the amount that street gasoline EVER had, so it's really not good for long term use in a two-stroke engine, and certainly not a 'low lead' formulation by street gas standards.

Back when all street gasoline had lead in it, there was this special gasoline we used to call "Amoco White Gas" which, while a high octane rated fuel, contained NO lead at all. This was the recommenced fuel for two-stroke outboard engines, since lead will foul spark plugs and leave lead deposits on the piston crowns on two-strokes. The only problem with the stuff was that you could only buy it at a marina, and you had to pay about 25 cents extra per gallon over street premium grade. Nevertheless, I used to make special trips to a local marina to get 'Amoco white gas' for my Maico dirt bikes.

For the longest time, a marina was the only place you could buy the stuff. Then in the early 80's it began to show up at Amoco gas stations under the name "Amoco Ultimate" in anticipation of the phase-out of lead in US street gas in 1985. Now that formulation has basically disappeared again, except at some marinas.


Jimbo

[naturewaterboy]

We do have a gas station on Plantation Key that advertizes no ethanol (i think 90 octane) gas. The station is owned by a fuel distributor here.

[naturewaterboy]

Ok, I talked to Mercury Marine about putting filters between my outboard engines and my fuel tanks - their answer was "don't do it". She explained that my 2008 Optimax 225s have fuel filter/water seperators built onto the engines. An additional filter will cause a restriction and the engine won't be able to suck gas thru the additional filter.

After talking to the Mercury factory, I talked to my local shop - very highly regarded shop - the owner told me that Mercury used to recommend not putting filters in, but they started recommending them because of ethanol - that boats need the extra water separator capacity. Also, if the filter clogs or gets filled with water while at sea, pulling the cowlings off the engines and climbing out to fiddle with the filters on the engine is a p.i.a. - so filters inside the boat are the way to go - but apparently they need to be clean enough to not cause too much restriction.

[powerabout]

ALL gasoline intended for use in automobiles in the US MUST contain 10% ethanol, including here in FL. But the marinas succeeded in getting an exemption from this requirement, so you can get ethanol-free gas, including the *original* Amoco ultimate at your local marinas.

100LL runs fine in 4-stroke engines, but is no good for 2-strokes. Remember that while the 'LL' in 100LL (http://www.sportys.com/terryc/images/1999m.jpg) (blue) stands for 'Low Lead', this 'low' is only in comparison to the older '100' (http://www.aircraftspruce.com/catalog/graphics/09-42808.jpg) (green) grade of avgas. 100LL actually contains an enormous amount of lead (as TEL) at 2 grams/gallon, about twice the amount that street gasoline EVER had, so it's really not good for long term use in a two-stroke engine, and certainly not a 'low lead' formulation by street gas standards.

Back when all street gasoline had lead in it, there was this special gasoline we used to call "Amoco White Gas" which, while a high octane rated fuel, contained NO lead at all. This was the recommenced fuel for two-stroke outboard engines, since lead will foul spark plugs and leave lead deposits on the piston crowns on two-strokes. The only problem with the stuff was that you could only buy it at a marina, and you had to pay about 25 cents extra per gallon over street premium grade. Nevertheless, I used to make special trips to a local marina to get 'Amoco white gas' for my Maico dirt bikes.

For the longest time, a marina was the only place you could buy the stuff. Then in the early 80's it began to show up at Amoco gas stations under the name "Amoco Ultimate" in anticipation of the phase-out of lead in US street gas in 1985. Now that formulation has basically disappeared again, except at some marinas.


Jimbo
Jimbo

Whats the problem of the 100LL in outboards?

Cheers
Powerabout

[naturewaterboy]

As Jimbo said above, it leaves lead deposits on the piston and on the spark plug, which interferes with proper combustion, which causes your motor to run really bad.

[Frosty]

Weve had E85 and B5 biodeisel in Thailand for years, you just getting it?

It makes no difference,- we went through all this crap "oh my Ferrari wont run on this stuff" its ok .

Its the 2 strokes that went on it first. I don't care any more what I use in what ever vehicle, I cant tell the difference, in fact I search for Bio.

[powerabout]

So what happens to all the guys racing outboards and using 100LL or 100 as cheap high octane supply?
There are some other sites with big long threads the pro's and cons of avgas but they never mention a lead problem?
hence my question?
maybe only long term problems with twice as much lead or low speed fouling? dunno

[Jimbo1490]

So what happens to all the guys racing outboards and using 100LL or 100 as cheap high octane supply?
There are some other sites with big long threads the pro's and cons of avgas but they never mention a lead problem?
hence my question?
maybe only long term problems with twice as much lead or low speed fouling? dunno

The answer is in your own post; there's no such thing as "Long Term" racing use! A boat owner wants to get 5 or 10 years of untroubled service from his engine. A real race engine comes apart no less than once a season, sometimes more often; sometimes MUCH more often:D

Jimbo

[powerabout]

fair enough

[FAST FRED]

The answer is in your own post;

LL stands for LOW LEAD ,

its not the avgas your grand daddy flew with ,

FF

[powerabout]

it still has to work with those same WWII engine though ya?
Is that why they have 100LL and the 100/130 now called 100

[Jimbo1490]

The answer is in your own post;

LL stands for LOW LEAD ,

its not the avgas your grand daddy flew with ,

FF
Fred.

It's only a 'low lead ' formulation compared to other aviation fuels, NOT compared to street or boat gas. 100LL has a LOT of lead when compared to street gas.

Jimbo