2001 GW 265 Fuel tank fabricator for repower mission

[Sketchywind]

Continuing my 2001 GW 265 repower mission.

If my boat surveyor gives the green light with no major structure damage, I’m going to finance a Merc repower from my 2001 HPDIs with 1750 hours and a blown port motor.

I pulled the decks yesterday and the tops and sides look pretty decent after a salt-away cleaning. I rinsed off the tanks 1-2 times a year, so not much crud on top. Used a borescope to verify no major “corrosion volcanos"

Going to have yard pull aft tank to inspect bottom after survey.

If tanks need replacement, what aluminum tank fabricator do you recommend? How much is estimated cost of new tanks?

I got transom rebuild estimate at $15K and Mercury V6 225HP with DTS estimated $60-65K here in San Francisco Bay Area.

I decided three plans for my 2001 GW265:
1.Repower, if surveyor gives a green light on no major structural issues other than transom rebuild. If fuel tanks are solid, go forward with repower. Estimated cost: $75K
2.Repower and replace fuel tanks. Estimated cost: $75K, plus new fuel tanks installed ($10k?) = $85K
3.Surveyor says boat has major structural issues and not worth repower: Bolt on used HPDI 200 and buy a newer used boat. Or sell it as project boat with blown port motor.

Here are before and after tanks after a little cleaning.

 

[SkunkBoat]

I know some good NJ tank shops but...You need to find a local tank fabricator because shipping tanks is crazy expensive.
As I said, you could get away with just the 130 gal main (fwd) tank. that'll give you at least a 180 mile range at 30mph.
If you want more, you could fit an aft prefab plastic 50 gal tank and have room for storage.

 

[Sketchywind]

Good idea. I don’t see myself running over that 180 range, but I got my hands on some tuna gear so possibly in the future.
Since I primarily used the forward tank, I was thinking if I replace both tanks to dedicate the aft tank as non-ethanol fuel only to protect it from the ethanol effects not using it frequently. Theres a racetrack nearby that sells non-ethanol 91 race fuel I can use portable fuel jugs to keep 25-30 gallons as back up fuel. Protect the tank from phase separation and corrosion.
Replacing tanks leaking or not may be a good move if investing in 65k motors.

 

[SkunkBoat]

Paying for a new 120 gallon tank just to keep it filled, so it doesn't go bad, seems kinda silly...
If they seem to be good, wait a year or two, spread out the pain...
If you are repowering and fixing a transom, you are committing to 10 years or more? You will eventually need the tank(s)

My boat had tanks replaced 6 months before I bought it. So luckily I wasn't dealing with that. (have replaced a bad 60 gallon tank on a 20' before)
I had ox66s that got 1 mpg and I did 200 mile canyon runs on full tanks and brought an extra 20.
With the zukes I get easy 1.5+mpg so I don't need 250 gals.
If I needed tanks, I would get the fwd tank and refit the aft tank space and deck hatch for a 50 or 75 and a really really insulated ice hold.
I'm just not going to pull a perfectly good tank...

As for ethanol, that has been a discussion for years.
I have never paid for non-ethanol fuel. Not that it is even available ...
I have not had any problem with E10 on this boat nor my last boat.
I only fill both tanks when prepping for a canyon run. I'll burn about 150gal on a 1 canyon trip but nice to have range to other canyons (so I can chase the dragon to another canyon and not catch what I was not catching in the first one....)

Otherwise I fill the fwd and put 50 gals in the aft and run the aft down to 10 or so and switch to the fwd and burn 60 and then start that over again.
Keeps the gas fresh. I run about 200 hrs a season (May thru Nov). I use a Valvetec gas dock that has 89 octane E10 that is already treated with Valvetec. If I use a different gas dock, I add Startron ...
Over the winter storage I have experimented with one full/one near empty. Neither has ever had a problem.

 

[Sketchywind]

Paying for a new 120 gallon tank just to keep it filled, so it doesn't go bad, seems kinda silly...
If they seem to be good, wait a year or two, spread out the pain...
If you are repowering and fixing a transom, you are committing to 10 years or more? You will eventually need the tank(s)

My boat had tanks replaced 6 months before I bought it. So luckily I wasn't dealing with that. (have replaced a bad 60 gallon tank on a 20' before)
I had ox66s that got 1 mpg and I did 200 mile canyon runs on full tanks and brought an extra 20.
With the zukes I get easy 1.5+mpg so I don't need 250 gals.
If I needed tanks, I would get the fwd tank and refit the aft tank space and deck hatch for a 50 or 75 and a really really insulated ice hold.
I'm just not going to pull a perfectly good tank...

As for ethanol, that has been a discussion for years.
I have never paid for non-ethanol fuel. Not that it is even available ...
I have not had any problem with E10 on this boat nor my last boat.
I only fill both tanks when prepping for a canyon run. I'll burn about 150gal on a 1 canyon trip but nice to have range to other canyons (so I can chase the dragon to another canyon and not catch what I was not catching in the first one....)

Otherwise I fill the fwd and put 50 gals in the aft and run the aft down to 10 or so and switch to the fwd and burn 60 and then start that over again.
Keeps the gas fresh. I run about 200 hrs a season (May thru Nov). I use a Valvetec gas dock that has 89 octane E10 that is already treated with Valvetec. If I use a different gas dock, I add Startron ...
Over the winter storage I have experimented with one full/one near empty. Neither has ever had a problem.

Yeah, I agree with your new aft fuel tank ethanol treatment just to keep it factory stock. My GW265 was a canyon runner out of Delaware. I’ve only run out the Golden Gate 25 miles to the Farallon Islands, but we’re getting Tuna running about 75 miles out again. So, the aft tank doesn’t really need to be there for me.
Borescoped top and sides after a more thorough top cleaning. Looks good!
I do need to change out my 25 year old fuel hoses rated A-2. I believe A-15 is the new ethanol standard.
Definitely a learning experience!

 

[SeaVee]

Wow. Crazy prices out there. 200 Zuki’s were 38k out the door here. That tank estimate sounds high, but I agree you don’t need 250 gallons with the modern 4 strokes. Go ahead and put SeaKeeper Ride on her while you are at it.

 

[Sketchywind]

Not sure what purpose of the wooden frame box under helm flooring above the forward fuel tank? The port side corner is loose and likely needs a few screws to brace it.

 

[SkunkBoat]

That looks different than mine, but my tanks were replaced so they probably took that piece out and replaced it with something. I’ll have to look around for a picture. My boat is covered up for the winter right now.
Question. Did you check the dates on the tanks to see if they have been replaced before?

 

[Sketchywind]

That looks different than mine, but my tanks were replaced so they probably took that piece out and replaced it with something. I’ll have to look around for a picture. My boat is covered up for the winter right now.
Question. Did you check the dates on the tanks to see if they have been replaced before?

Thanks! I realize now the 1/4” thick wood box is right under the big fish box compartment. It runs under the whole helm deck. A stainless corner bracket will secure the loose corner.
My tanks are original RDS from ‘01.

 

[Sea Shift]

Hey Sketch, I did this whole job last season. You can see my write up here......

Welding world supplied the tanks. I cant say enough about them. Professional, fast shipping. The replacement was fairly easy. The hardest part was getting rid of my bad gas.

https://www.greatgrady.com/threads/im-replacing-my-265-express-fuel-tanks-pic-heavy.38367/

 

[Sketchywind]

Hey Sketch, I did this whole job last season. You can see my write up here......

Welding world supplied the tanks. I cant say enough about them. Professional, fast shipping. The replacement was fairly easy. The hardest part was getting rid of my bad gas.

https://www.greatgrady.com/threads/im-replacing-my-265-express-fuel-tanks-pic-heavy.38367/

Thanks! Found your fuel tank post and looks like good project. I borescoped the bottoms today and amazingly they look clean and shiny. Can’t say for sure under the rubber feet, but I might have Grand Marina pull the aft tank to inspect. I’m going for repower with Mercs V6 225HP after a transom repair. $$$
My station 41 buddy said, “you’re only spending your son’s inheritance! “

 

[Aussie_Boss]

I’ve been through this exact job, and for me the most cost-effective option by a long way was pulling both tanks, cutting out the bad sections, replacing the affected sheet metal, coating the tanks, and reinstalling them. New tanks was not actually required.

Once the tanks were out and I could properly get into the hull, things escalated pretty quickly. I found the floor was soft and the stringers had water rot, so the money I saved on the tanks ended up going straight into new stringers and a new floor. It wasn’t planned, but it was unavoidable once everything was exposed.

And, as tends to happen with these boats, one project led to another. While I was that deep into it, I decided to install two through-hull transducers. That meant shifting the rear tank further aft, which then meant moving the rear bulkhead. None of it was impossible, but it’s a good example of how quickly scope creep can happen.

These boats are absolutely worth doing properly, but once you start opening things up, be prepared that you might uncover more work than you bargained for. At some point you also have to draw a line and say “that’s enough for this round,” otherwise every job turns into a full rebuild.