Mercruiser 5.0L carburetor/fuel tank problems -- drain/clean?

[dmillerss]

I had bogging issues past 2,000 rpms discussed in another post. After rebuilding the carburetor and replacing the fuel pump the boat ran beautifully. Four hours of event-free cruising, and then I filled up the tank. A half hour later, the boat bogged and backfired; tried to get it going again, more bogging and backfiring, and then it wouldn?t start. My question is: am I going to have to drain the fuel I just bought and get the fuel tank cleaned?

 

[alldodge]

I had bogging issues past 2,000 rpms discussed in another post. After rebuilding the carburetor and replacing the fuel pump the boat ran beautifully. Four hours of event-free cruising, and then I filled up the tank. A half hour later, the boat bogged and backfired; tried to get it going again, more bogging and backfiring, and then it wouldn’t start. My question is: am I going to have to drain the fuel I just bought and get the fuel tank cleaned?

If you know it's bad gas you just got, then I would say yes, you need to drain the tank. Now if it was water or something else maybe not. Can you provide a bit more detail on your issue?

 

[dmillerss]

The boat would not go past 2,000 rpm for weeks, but she started and idled just fine. So I replaced the fuel pump, cleaned the filter, and cleaned the carb. The boat ran beautifully, better than she ever had before, at 4,000 rmp for a couple hours. Then I went and filled the tank; a half hour later the boat backfired and died, and wouldn't go past 2,000 rpm's again. I would really like to know if I just just keep cleaning the carb and filters when this happens, or do I should I have the tank drained and cleaned. I don't think it's bad gas; I'm afraid there's some sort of corrosion in the gas tank (probably because of the Ethanol, even though I always use Startron). I don't think that replacing the fuel tank and I imagine cleaning it is not an easy thing to do. But if you Iboat answers think that I should replace or clean the fuel tank I will .... thx much, DMiller

 

[alldodge]

Pull the filter and dump contents into a zip lock bag. See what the contents look like and if there is crud or water in there

 

[NHGuy]

Maybe you will find junk in the separator, which means it did it's job to save your carb. If that's the case change the separator and try the boat again. Never reuse those filters, once you remove them debris gets on the other side of the filter.

 

[Bondo]

My question is: am I going to have to drain the fuel I just bought and get the fuel tank cleaned?

Ayuh,..... Here's My take on it, 'n how I deal with it,.....

If the tank itself is Ok, 'n it's just crud, 'n water in it, figure out exactly where the diptube pulls from, 'n the relation of the tank's bottom to level, to the hull on the trailer,...
Now the crud, 'n water will always be on the Bottom of the fuel tank,.....

I built my own "Fuel Polishing" system, with an electric fuel pump, a Mack spin-on filter that holds nearly a gallon, 'n a kit of hoses, 'n fittin's,...
I plumb my System from the tank's fuel line at the boat's fuel filter, run it to the Mack filter, to my electric pump, back to the tank's fill,....
Jumper it to a battery, 'n let 'er run,....
After awhile, raise or lower the trailer jack, move the bubble of water, 'n crud to the diptube, to pump it out,....
If necessary, jack up one side, or the other, of the wagon,...

With alittle Luck, the water, 'n crud amounts to slightly less that the Mack filter holds,....
That saves my electric fuel pump,....
With alittle more luck, the anti-siphon valve passed all the junk,...

Ya might carry a spare fuel filter, in a freezer baggie,....
If ya have another issue, it ain't bad to swap out the filter on the water,....
Loosen it, slip the baggie 'round it, spin it off, drop it in, 'n zip it up,...

Spin on a new one, 'n hopefully, yer boatin' again,....