Gunk in the fuel tank

DArcy

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Feb 11, 2017
1,702
Islander Freeport 36 Ottawa
So I've been having problems this year with crap in the fuel. I have an Atomic 4 which has a sediment bowl attached to the fuel pump and I added a filter in line before the pump several years ago. In the spring the engine was running rough so I checked the filter, lots of gunk. I cleaned the sediment bowl, lots of gunk. Putting the bowl back on I noticed the gasket was shot. I tried to make one out of some gasket material but that didn't go well. I was going to order a new one but decided to just get a whole new fuel pump because shipping was 10x as much as the gasket so why not make it worth it and shell some out more money. This is a 44 year old engine, I'm replacing it one part at a time.

Anyway, while waiting for the pump, I cleaned out the carburetor (lots of gunk). I installed the new pump and fire it up. Ran like a champ... for about 2 hours then crapped out again. More gunk in the filter. Now I know I have to bite the bullet and clean the tank. I called around to find someone to do this for me but no one wants to deal with it near water and the tank is about 1" too big to fit out the hatch. I figured I might as well give it a try. I have decent access above the tank so I figured I'd take the fuel sender and fuel inlet hose out and have a look. The tank is Monel so I was pretty sure it wasn't rusting. A few years ago the fuel gauge stopped working so I ordered a new fuel sender. I've had it over a year, just never go around to installing it. As I was getting the tools out to remove the sender I had an Aha moment. Sure enough, the fuel sender was rusting away.

So where did the rest of it go? Yup, you know where.

Notice the fuel pick up hovering right over the gunk.
I have a Pela 6000 oil extractor which was fantastic for this job. Pump it up then wave the hose around in the bottom of the tank sucking up the crap. I was amazed how well it worked. A little while later...

I cleaned the carb again and it fire right up, ran great for the test run.
 
Oct 22, 2014
21,085
CAL 35 Cruiser #21 moored EVERETT WA
Good solution to a standard problem that faces a boat owner sooner or later.
 
Mar 26, 2011
3,410
Corsair F-24 MK I Deale, MD
You need to start using an additive that inhibits corrosion. Biobor EB or Merc Easy Stor. They really do help and will stop this sort of corrosion dead. It also looks like water has been getting in the tank, probably through a filler leak. Even a few drops of saltwater are deadly. In breathing is another possibility. The steel would NOT have corroded like that unless something else was wrong (I've done a lot of testing, lab and field). Carbs have lots of steel parts. There is water in the tank and probably salt also. I'd make an effort to burn through the rest of the gas soon, or simply remove it.

http://sail-delmarva.blogspot.com/2017/05/100-best-buys-chapter-3.html
http://sail-delmarva.blogspot.com/2012/11/gasoline-and-fuel-tank-vent-filters.html

The oil extractor idea for sumping tanks is easy, smart and safe. Spread the word!

(35 years in the fuels business as a Chem E)
 
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