Fuel question...

Colorado04

Petty Officer 2nd Class
Joined
Aug 29, 2005
Messages
165
I installed one of those little glass bodied inline fuel filters. The ones that come apart so you can clean/replace the screen inside.

I noticed couple of things...

1. the fuel in the filter/glass body, after it sits for a day goes from clear to a deep yellow, almost a tanin color. Is that normal?
2. sometimes when the motor is running, the filter is empty. The motor still runs, and the filter fills up again. Is that normal or is it supposed to be full all the time and I have an air leak somewhere? When the fuel is flowing, I don't see any air bubbles come through...

Thanks in advance.

Donnie.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Fuel question...

Here's what I'd do: replace that little glass unit with a water/fuel separator cartridge type filter mounted on your transom. Walmart/Attwood unit is $27, easy 2 screw installation. It'll do a much better job of filtration And separating any water in your fuel system. Start using a fuel stabilizer like Stabil or Seafoam all the time, lots cheaper than gummed up carbs, injectors, screens, etc. Save yourself a lot of fuel related problems down the river! Good Luck!:)
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: Fuel question...

If, when you pump the bulb, the filter fills full then runs empty, I'd say you're sucking air from somewhere. It, the inline filter should be just before the carb/s. Ro..grah..'s water seperating filter should be just after the tank. If it's running good I wouldn't worry about the color. Running lean is worth a worry.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Fuel question...

on a boat the fuel is sucked from the tank unlike a car where it is pumped from the tank so it will drain the filter when running, I have a similar set up on mine and it is normally mostly empty but the engine always runs fine, that is why the bulb doesn't stay hard too, as sson as the engione is started it sucks the fuel out and relieves the pressure but is normal.

As to the color I can't say, maybe the sun is doing it, never notice that in mine but it is kept in the garage.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Fuel question...

Glass inline filters should be outlawed. They cause untold needless worry about the air in them. It is normal, and you can work your way to a frenzy trying to get rid of the air. Ain't gonna happen.
 

Colorado04

Petty Officer 2nd Class
Joined
Aug 29, 2005
Messages
165
Re: Fuel question...

Thanks alll for the advice/info.

I definately want to go to a better filter/seperator setup. I mainly want to use the little glass filiter to check flow. Afterwards, I used clear hose temporarily to check flow and there was no air in there. Full of fuel from the tank to pump. As to the color of the fuel, I think it may be leaching from the fuel line. I took a look in the tank and the fuel was clear. Maybe I got some bad line. Got it from the local auto parts store. It seemed a little soft/stickey on the the outside. Guess I'll go and get some more from another store.
 

SolingSailor

Petty Officer 2nd Class
Joined
Dec 24, 2009
Messages
197
Re: Fuel question...

My inline filter also shows an empty space when the engine is running. There has never been a problem, and I've wondered if it is actually air (where does it come from? backwards from the engine? it is at the low point in the line, near the tank.), fuel vapor due to the vacuum, or just a small area of vacuum.
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: Fuel question...

Thanks alll for the advice/info.

I definately want to go to a better filter/seperator setup. I mainly want to use the little glass filiter to check flow. Afterwards, I used clear hose temporarily to check flow and there was no air in there. Full of fuel from the tank to pump. As to the color of the fuel, I think it may be leaching from the fuel line. I took a look in the tank and the fuel was clear. Maybe I got some bad line. Got it from the local auto parts store. It seemed a little soft/stickey on the the outside. Guess I'll go and get some more from another store.
Only use Marine Specified Fuel Hose, not automotive. With the ethanol and additives the automotive hose just won't hold up. Ditch the glass filter for the fuel/water separator type, don't look at or worry about the "air in the hose". When you get the real "Marine" hose your color issue will most likely disappear! Good Luck!:)
 

foodfisher

Captain
Joined
Feb 18, 2009
Messages
3,756
Re: Fuel question...

The inline filter before the carbs will protect the carbs from disentegrating primer bulbs and fuel lines that would otherwise cause carb problems and possible lean running engine failure.
 
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