What is the fuel filter supposed to look like?

[Danny C]

I just replaced a switchbox and was on the water to troubleshoot what I thought was electrical issues (intermediate spark) when I noticed the inline, clear, fuel filter was almost empty. I would assume that the filter is an extension of the fuel line and should remain full. I also noticed that it looks like there are bubbles in the fuel coming to the filter. I recently replaced the lines and filter because my old lines would leak fuel and these new lines seem airtight. I do not know where air would be coming from unless it is from my tank being almost empty.

Symptoms - launch boat, idle out, go WOT and run for about a minute fine and then it fell flat on its face to about 25% power. From there it will only run 25% and sputters and spits the whole time doing it. I also noticed that the bulb was soft. If I pumped the bulb until it was firm I could go WOT for awhile until it would start sputtering again. The whole time my fuel filter level was fluctuating and looked like it was starving and lots of bubbles. I plan to rebuild fuel pump tomorrow and maybe try to replace fuel lines although I do not know where the air would be coming from.

I think this whole issue started when I sucked up some water from the gas tank. I have not pulled the carbs yet but hope I don't have to. The carbs should not have an effect on the amount of fuel getting to them from the filter would they? Should the filter be full at all times? or is the fluctuation and air normal?

Thanks,
Dan

 

[ondarvr]

The fuel filter may not appear full and can be fine, but there shouldn't be bubbles entering it. The air could come from anywhere, and if the tank is low fill it and see if that helps, you may have a leak in the pickup tube. If squeezing the bulb makes it run correctly, then the water probably has nothing to do with it. Could be a suction side leak or bad fuel pump.

 

[Tnstratofam]

The inline fuel filter on my outboard stays about half full all the time when running. It sounds more to me like you are sucking air somewhere between the tank and the filter. Check all of your connections. Also just because a line is new doesn't mean it can't be bad.Trust me I found this out the hard way.

 

[GA_Boater]

Sounds normal to me. Mine looks between 1/2 and 3/4 full, even after pumping 'til firm and runs fine. No bubbles, just not full.

 

[Danny C]

I agree, that I think I am sucking in air from somewhere. I plan on replacing all lines, pump, bulb, and filter tomorrow.

I would be ok if it stayed half full but I can watch it fluctuate and run pretty much empty. With my old fuel lines, I could pump til firm and I could see gas leaking at joints which is why I replaced them. Now I can pump till firm and if I squeeze hard on the bulb I get no gas leaks and feels like I am putting some decent pressure on the system where if I had a leak, I would be able to pump the bulb. and push gas/air out of the system.

 

[zul]

What color should the gas be while in the fuel filter? As in ... when does the inline filter pick-up oil? Shouldn't the fuel in the fuel filter already have oil in it (NOT clear??) ... say light green color (or gas mixed with your fav 2-cycle oil)? I don't have air bubbles but I think that my oil pump is not injecting oil consistently, giving me some similar problems (and not starting).

 

[GA_Boater]

What color should the gas be while in the fuel filter? As in ... when does the inline filter pick-up oil? Shouldn't the fuel in the fuel filter already have oil in it (NOT clear??) ... say light green color (or gas mixed with your fav 2-cycle oil)? I don't have air bubbles but I think that my oil pump is not injecting oil consistently, giving me some similar problems (and not starting).

Please start a new topic. You are asking about a different type of problem.

 

[Danny C]

You are Correct GA, different type of issue. I premix my oil/fuel and don't have oil pump. My gas is greenish and looks like I believe it should in the fuel filter (except the bubbles)