20 year old varnish in tank 208

[Sardinia306Canyon]

His opinion, "Trash the tank" even if you clean it there will always be an issue, because as he put it "you can never really clean a tank that is so bad no matter what you do." Just when I thought I would get a chance to enjoy this boat, damn!!

I would say the same, independent if tank is made of aluminum or plastic.
26 year old aluminum will show issues sooner or later and poly tanks from 2000 are different and lower quality from the ones built today.
Troubles with dirty fuel is probably #1 reason for needing a tow and leaking fuel tanks happen usually just in the beginning of the season.

I did the same in 2023 when the fuel tank of my RIB leaked and i had to use a external 20 gallon tank strapped down on deck,
ugly looking and using deck space, but i could use the boat for 10 months till i replaced the tank during winter.

Chris

 

[310des]

I ran the motor today on an external tank. I had to remove the internal fuel filter to get it to run but eventually it did. Idle was rough and when I punched it there seem to be a bit of a dead spot before it kicked in. I'm going to run an external tank for now so I can use the boat. I found a guy who cleans
boat tanks here in new jersey. He's seems experienced since he's been at it for like 20 years. His opinion, "Trash the tank" even if you clean it there will always be an issue, because as he put it "you can never really clean a tank that is so bad no matter what you do." Just when I thought I would get a chance to enjoy this boat, damn!!

I had similar issues with an88 204C. Atlantic Coast Welding Bayville made new tank. All fuel problems solved.

 

[rmf4grady]

I would say the same, independent if tank is made of aluminum or plastic.
26 year old aluminum will show issues sooner or later and poly tanks from 2000 are different and lower quality from the ones built today.
Troubles with dirty fuel is probably #1 reason for needing a tow and leaking fuel tanks happen usually just in the beginning of the season.

I did the same in 2023 when the fuel tank of my RIB leaked and i had to use a external 20 gallon tank strapped down on deck,
ugly looking and using deck space, but i could use the boat for 10 months till i replaced the tank during winter.

Chris

Went to the boat today. It's so hot here, 100F, so I just ran the engine on an external tank for a while with some fuel injector cleaner added. Seem to be idling better now. Replaced the low-pressure fuel filter. Eventually I'm going to remove and clean the injectors, replace the high-pressure fuel filter and remove the VST and clean. I decided to take a sample of the gas straight from the tank. I found 50/50 gas and water, probably because the boat is on an angle, its' ass-end is lower. The leak, well I',m guessing it's the fuel input, either because the cap wasn't tight or there is some leak in the o-ring there. We had some heavy downpours so maybe that did it.

 

[seasick]

So how did you confuse varnish with water?
If the tank is half full of water, I suggest you pull the sender and use a hand pump to siphon/pump out the water on the bottom of the tank. You should be able to tell by color and smell when you got most of the water and when yu are pumping gas. The water can be disposed easily and if you get to gas, just pour that back into the tank since it is relatively new. Some folks use the old gas in their mowers and similar equipment but based on my experience, if it looks like good gas and smells like good gas, it is OK to use. Don't spend hundreds maybe thousands on replacing tanks etc yet. Water separators and engine filters yes. You said you bypassed the motor fuel filter? That is a really bad idea.

 

[rmf4grady]

So how did you confuse varnish with water?
If the tank is half full of water, I suggest you pull the sender and use a hand pump to siphon/pump out the water on the bottom of the tank. You should be able to tell by color and smell when you got most of the water and when yu are pumping gas. The water can be disposed easily and if you get to gas, just pour that back into the tank since it is relatively new. Some folks use the old gas in their mowers and similar equipment but based on my experience, if it looks like good gas and smells like good gas, it is OK to use. Don't spend hundreds maybe thousands on replacing tanks etc yet. Water separators and engine filters yes. You said you bypassed the motor fuel filter? That is a really bad idea.

When I looked at the mucky brown stuff I got before I thought it was dirty gas. But it was
probably more from the water/fuel Seperator bowel than the tank, I mixed the two. When I took only from the tank it looked like classic water/fuel mix, pristine fuel on top and mucky brown stuff on bottom. Now the mucky stuff might have some varnish in it I don't know. I'm going to tip the bow up and pump out the gas through the fuel sender port then through a water/fuel Seperator finally then back into the tank. I've seen it done before on YouTube so it seems straight forward to implement a simple rig. I'm really happy if this is the problem because it seems curable. I agree no filter is stupid, so I replaced the low-pressure filter already. Thanks for the input, I appreciate it!!

 

[seasick]

When I looked at the mucky brown stuff I got before I thought it was dirty gas. But it was
probably more from the water/fuel Seperator bowel than the tank, I mixed the two. When I took only from the tank it looked like classic water/fuel mix, pristine fuel on top and mucky brown stuff on bottom. Now the mucky stuff might have some varnish in it I don't know. I'm going to tip the bow up and pump out the gas through the fuel sender port then through a water/fuel Seperator finally then back into the tank. I've seen it done before on YouTube so it seems straight forward to implement a simple rig. I'm really happy if this is the problem because it seems curable. I agree no filter is stupid, so I replaced the low-pressure filter already. Thanks for the input, I appreciate it!!

Just as a heads up, if you pump out a sample and let it sit, you should see two layers, water and gas. If you see 3 layers, you have phase separation and the gas has to be disposed. Using the gas from phase separation can seriously damage your motor.

 

[rmf4grady]

this is right from the tank

 

[seasick]

OK. Pump out the water.

 

[Hookup1]

this is right from the tank

What are you using for a pump? When you pump out thru the fuel line (with the bow elevated) you can get most of the water out of the tank. The pickup can only get so close to the bottom of the tank so there will be some still left. I got it out by running the boat and shaking the fuel up in the tank (running over wakes, hard zig-zag turns). This will get the water sucked up in the fuel filer. You need to keep an eye on it though so it doesn't fill up and stall your engine.

Seasick's point about phase separation is important. The "water" in the bottom of your bottle is your ethanol and water. The fuel on top is compromised in that it has lower octane. Don't run the motor too hard and listen for knocking. When you are sure you got most out add 20 gallons of premium fuel and run it some more until filter/water separator remains clean. You need to get all the water out before adding more fuel otherwise it could separate the ethanol out of the new fuel.

Have you checked your deck fills yet for o-rings?

Ethanol and Older Engines

What is it about older boats that make them more susceptible to ethanol's well-known problems?

www.boatus.com

 

[Sardinia306Canyon]

I personally would not suck the water out by the engine as water ethanol mix may get in engine.
Unscrewing the sender and sucking it out with a hose on ass-down boat and drain it in jerry cans or barrels is more safe.
Depending on hight this can be done by gravity, if not a fuel pump for cars will do the trick, but slow.
Most expensive but safest solution would be calling someone who do that for life.
Chris