20 year old varnish in tank 208

[Sardinia306Canyon]

Do yourself a favor - get the tank professional cleaned and fuel polished. Or replace the tank.

THIS!

Beside the risk for life of people when having a non starting engine on the water you risk the life of your engine as well.
Invest the money for a professional tank cleaning or then just repalce the tank even if you need to cut, get a quote for that by a reputable fibreglass shop.

Chris

 

[rmf4grady]

I dont know what 'pure' crap means. Was it water, ethanol, other gunk? Which filters get gunked up?
Do not cut the pickup. That won't fix the issue and will limit how much usable gas you can have in the tank
Remove the sender and use that opening to manually pump out from the bottom of the tank.

Note that when you accelerate to get on plane and at speed, the bow lifts up. When that happens, the contents of the gas tank collect in the aft area of the tank. If you had a half inch of gunk in the bottom of the tank at rest, when tilted the level of the gunk will be higher. How high depends on the angle and the geometry of the tank. Regardless, you have to get the gunk out of the tank.

It's not water but discolored gas. The color is darker than regular gas but not very dark like I had seen before. So, when I first start the engine after removing all the gas from the tank (I go in through the hole for the sending unit with the boat on and angle) and putting in new gas the motor runs on this stuff, and it doesn't really seem to be an issue. Over the long-term running on that gas would gunk up the injectors but maybe it wouldn't, I don't know. Eventually the small fuel filter in the motor clogs. That is the 10um low-pressure filter, it's physically small so doesn't take much to clog it. I have a external 10um water/fuel separator that stays ok, but that's a big filter. So, the varnish on the bottom of the tank must be dissolving into the gas, and since it weighs more it just stays there. Yea when I'm pushing the boat the angle of the bow increases. So, I calculated that even if I had roughly 3 gallons of this gas on the bottom of the tank if I raise the pickup and inch from the bottom I wouldn't suck up the bad gas. Of course, that's theoretical and doesn't account for the mixing of the bad gas with the good stuff, but I'm stuck here. Can't find anyone how would clean the tank and to replace it would probably set me back 8-10K because for my year you have to cut the deck to remove the tank. External tanks are at most 24 Gallons which isn't enough. If I could remove the water tank from under the deck and replace with say a 35-gallon fuel tank, I would go for that. Probably have to bite the bullet and replace the tank.

 

[Hookup1]

If you are telling me this stuff is on the bottom of the tank then it is separate from the fuel on top. Are you adding ethanol fuel to a water contaminated tank? Then sure you are making more water in the bottom of the tank. It’s called phase separation. When you stop for a while it will drop back out to the bottom.

You absolutely will suck it up no matter where the pickup is located. When you run the boat all the stuff on the bottom will mix into suspension in the fuel on top. While you run it will get into the filters and stop the engine.

Get the tank professional cleaned or replaced. Did you check those o-ring yet?

Let us know how it eventually gets solved.

 

[Sea Shift]

update: drained the tank 2 times. Both times I put in new gas and the boat ran fine at low rpm. After some time I upped the spped and the motor died out. Had to be towed back. Issue is the fuel filters get clogged. I drain the gas and the first 1/2-gallon's pure crap. The rest of the fuel looked good. I'm going to try and cut the fuel pickup by about an inch (should be about 7 gallons an inch for my tank) and hopefully most of the crappy gas will stay on bottom for the most part. To remove the gas tank requires me to cut the deck from the seats to behind the water tank, remove the water tank and cut out the crossmember (which is glassed in) between stringers . Thats because the tank has to be slid back about a foot to get it out. Why they built it this way I don't understand. A new tank is 2500 plus any labor I dont do..I think for labor it would be about 45-50 hours. 10 to get the deck cut, 15 to repolace the tank and 25 to reglass

Eeeekkkkk,
Im cringing because the one thing I haven't heard you mention is the injectors. I had the same issue with fuel. I removed the old fuel (looked just like yours), replaced my tanks, and had the same issues. It ended up being my injectors were WAY fouled. I had them cleaned and now the engines are purring like brand new. You might try that before the drastic measures.........

 

[Hookup1]

It's not water but discolored gas. The color is darker than regular gas but not very dark like I had seen before. So, when I first start the engine after removing all the gas from the tank (I go in through the hole for the sending unit with the boat on and angle) and putting in new gas the motor runs on this stuff, and it doesn't really seem to be an issue. Over the long-term running on that gas would gunk up the injectors but maybe it wouldn't, I don't know. Eventually the small fuel filter in the motor clogs. That is the 10um low-pressure filter, it's physically small so doesn't take much to clog it. I have a external 10um water/fuel separator that stays ok, but that's a big filter. So, the varnish on the bottom of the tank must be dissolving into the gas, and since it weighs more it just stays there. Yea when I'm pushing the boat the angle of the bow increases. So, I calculated that even if I had roughly 3 gallons of this gas on the bottom of the tank if I raise the pickup and inch from the bottom I wouldn't suck up the bad gas. Of course, that's theoretical and doesn't account for the mixing of the bad gas with the good stuff, but I'm stuck here. Can't find anyone how would clean the tank and to replace it would probably set me back 8-10K because for my year you have to cut the deck to remove the tank. External tanks are at most 24 Gallons which isn't enough. If I could remove the water tank from under the deck and replace with say a 35-gallon fuel tank, I would go for that. Probably have to bite the bullet and replace the tank.

Where are you located? Maybe someone can get you a someone to polish that tank.

But keep in mind a 25yo aluminum tank is about due abused or not.