Twin 2007 DF150's were perfect but now one stalls after a few seconds

[HWS234]

I had neglected running my engines 6 months (during our big Texas freeze) so last year I had to drain and rinse my tanks and replace one complete fuel module and one fuel pump. i run my engines every month and today I was idling one engine for about 10 min when it went from smooth to rough then died, out of gas! Racor fuel filter was empty but residual gas from fuel module was reddish. I added 12 gal gas and restarted but it would only run for a few seconds. Seemed starved of fuel so I am guessing that the last bit of fuel had varnish and gummed up the needle valves or the filters (I added alot of stabilizer). Also, If I waited a 5 minutes between starts it would run 5 seconds longer but still died. I will try adding Seafoam to the Racor filter but that is all I can think of. Also installed 2 new batteries last month.

Any options or clever ideas for dissolving or ungumming the system before I pull everything apart to find the blockage.

[Murray]

I’ve had good luck with a 50/50 mix of Seafoam and fuel. Check out Seafoam’s website. You should first drain the entire fuel system first and jerry rig a small fuel container with the mixture. I have never tried this with a Suzuki outboard but have successfully given this treatment to a lawnmower and 2 cycle weed wacker. Have you checked the condition of your fuel lines looking for internal deterioration? Inline fuel filters clear of debris? Check fuel pressure? You mention draining the fuel module, I’m ASSUMING that is the VST, any sediment in the container you collected the “red fuel” in? Fuel vents clear of obstructions? I would suggest you inspect every inch of your fuel delivery system, pulling every fuel line checking for internal damage, all clamps tight, no kinks… Checking everything won’t cost anything but will be time consuming. You may have to dig deeper but there is a lot you can check before you have to disassemble anything.

[artdf175]

Like Murray mentioned the VST
there are 2 filters on the engine
the low pressure -pre fuel pump .. that should catch must of the gunk-- then in the VST - at the bottom of the high pressure pump there is another with a even finer screen filter..
since you know you had some bad fuel, besides checking fuel hoses as Murray mentioned, I would take and open up fuel lines and use a air hose to blow all the fuel out.
If you think anything got past the high pressure pump take and open up the fuel rail and blow that out as well..
the sea foam should clean the injectors if anything got that far
Art

on the remote - the lever to increase RPM without engaging gears- will that work in keeping it running?

[HWS234]

Problem solved and sorry for wasting everyone's time as it was easier than expected. I assumed the worst.

I had a 2.5 gallon tank rigged with a fuel line from my last fuel debacle and connect to the Racor but no change so took off the Racor Fuel filter and it was plugged as shown (embarassing). Changed filters added 6 ounce Seafoam to the filter and the rest to about 1.5 gallons on ethanol free gas and it runs great. took a little while to move out the Seafoam but works great. t seems those nodules were sucked into the fuel line as the tank emptied. Could be leftover from last year but I rinsed each tank twice with 10 gallons gas; however, the boat is on a trailer and the angel was not steep. Could be from this years but I added double doses Stabil 360 and Stabil Storage but these are 125 gallon tanks and we had a 3 day hard freeze. Will get it into my lift and I put a serious angle before rinsing again.

This is a really bad case of neglect because I was rewiring the 26' Glacier Bay , new electronics and replacing pumps and floats so did not pay attention the engines and fuel. Also, I had another boat to fish.

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[Murray]

I’ve never seen fuel like that. What caused the “nodules”?

[HWS234]

There are probably some fuel experts who know the answer but I am guessing the low fuel level salt air, high humidity and freezing conditions contributed to crystals forming on impurities (maybe salt crystals were the start). I am installing inline clear fuel filters to screen these crystals out before the Racors. Moral of this story is to keep tanks 50% full, do less bay fishing and more offshore fishing I may try to dissolve them for kicks.

[Moonlighter]

Ive seen that kind of stuff before. It CAN be the inside lining of fuel lines deteriorating due to ethanol fuel incompatibility. BAD and it will continue to cause problems.

I recommend that you look closely at the fuel lines between tank and that Racor filter. very hard to see whats happening inside but if you take them off you may see/feel the lining coming apart if you flex the lines.

Personally I would replace them with proper marine grade, ethanol rated fuel lines just to be safe.