91' Mako 221 Fuel tank replacement/Rewire

[hunt-mor]

Started today on this project, i will try to keep it as updated as possible. Seems like a lot of good threads i read don't have anymore pictures due to the photo bucket change.

the only problem with the tank is it seems dirty as once a year our internal filters in the yamaha clog up. So it may be preventive maintenance right now, but i suspect theres corrosion as its a old tank and the sealant around the coffin is compromised in some spots. So with that said, ill be tackling the tank and maybe doing a rewire job under the console, depends what im feeling when i finish doing the tank

[hunt-mor]

Pictures from today, it was a easy derigging since i cleaned up the wiring last year and anticipated taking the tank out so i made sure that it would all come apart easy.

[hunt-mor]

Finished up the last of derigging today. Disconnected the steering and throttle. Console is ready to come up, Saturday looks like the day. Boats still outside, hopefully can move it in saturday, but its going to be 50degrees out so im thinking get console off, rip the coffin lid up, and start cutting foam out. Drained 45 gallons of gas out today also.

[BlueCrab]

I have a '92 221. I have been wanting to replace the tank but I am nervous of what I may be getting into.

I have a T-top as well and was thinking of trying to pull the console with top still attached but I am trying to come up with ideas to lift it in one shot.

I can not wait to see your progress...

Good Luck

[hunt-mor]

quote:

---

Originally posted by BlueCrab


I have a '92 221. I have been wanting to replace the tank but I am nervous of what I may be getting into.

I have a T-top as well and was thinking of trying to pull the console with top still attached but I am trying to come up with ideas to lift it in one shot.

I can not wait to see your progress...

Good Luck

---

Thats how we took the console off today, i left top on and the pipe gives you something to lift with too.

[hunt-mor]

So made a ton of progress this morning. Ripped the console and coffin lid up exposing the fuel tank. Did this all with only finding two stripped screws so it went very smooth. The tanks condition doesn't look so good. I already found two holes and lots of pitting in just one small area. Haven't started digging the foam out yet but its pretty wet haha so i expect to find more pitting. Right now its in the classic mako tank full of mold, corrosion, and a terrible smell. Cutting is not going to be fun but i should have a couple extra hands.

Console seal is broke, ready to move. Left the ttop attached, really helped with moving it since you have some leverage



Console moved up on the bow platform, out of the way.





Breaking the seal on the coffin lid wasn't hard, lots of the sealant was compromised so once i cut the caulk line and popped the corner up the rest of the lid followed.



Getting a first look at the tank, its a big tank but theres lifting points on each end so it shouldn't be a problem lifting it with the forklift.

[hunt-mor]

So i went back in the afternoon and started cutting the foam out around the tank. Well.....theres definitely a lot of wet foam in this coffin. I sawed and cut for about a hour, then tried popping the tank out. Had the boat off the rack but it wouldn't budge. Ill go back tomorrow with some extra hands and try getting it free.

[hunt-mor]

Today I noticed two things while cutting all the foam

One...the coffin has been cut and glassed back in which can mean two things. That mako messed up at factory at had to do something or the previous owner put a new tank in before we bought it in 2005ish. So Ill have to see what the deal is once I get the tank out. I cant make out the id tag on the tank its too worn out.

Two....the tank is coated and I thought mako never coated the tanks? While the tank is in decent condition it still has pitting over the tank up top at least, I havent been able to inspect it since its still in the coffin. Any input on this?

Anyway, I sawzalled around the foam and dug for a few hours today. Laid a stack of 3 2x10s across the stern, put a floor jack on top and tied off the tank and left it under some pressure for the night, maybe it will work itself free. Hopefully can get the fork lift to it tomorrow and see if it yanks out this time

[hunt-mor]

Well, most of the day was a rough one. The 3-4 hours of cutting i did yesterday weren't enough. When the forklift tried getting the tank, it was still taking the rest of the boat with it. It was a bummer since i really didn't know how much more i could cut. So, i dug all the foam out with a handsaw(because thats how little workspace i had) for a couple more hours.

When all of it was out, i decided to try the floor jack instead. And instead of the 2x10s across the gunnels, i tried 2x6s and 2x4s laid out on the deck so there would be no bending in the wood. Tied the floor jack to the tank with some old winch rope and after 3 pumps if started making noise and with a couple more the tank popped up! I started working on it at 10am, and at 4pm the tank was out. Foam was wet underneath, and it looks wet under the coffin too. I got to see how the PO cut the coffin out too. Big step.

So, i have no need for a 150g tank, im thinking of putting a 100-110 gallon tank instead?



Digging foam



Floor jack set up





Tank out, exposing the coffin





Where the coffin was cut

[snappergapper]

Congrats on the talk pull. Big step. I agree smaller tank and pushed all the way forward. i wish I would have done that to help with the newer motor. I nicked mine when installing the live well so If I ever have to do it again it will be moved under the console. I have 113 Gal. The most I have used is 70 gal. That was a 240 mile day. Lots of driving and trolling.

[hunt-mor]

Thanks. Ya it was definitely the hardest part, just no working room to dig easy. 100gallons will be more than plenty, and i won't mind keeping the tank topped off either now. I guess ill have to cut another hole in the coffin lid to have a hole to access the sender then.

I wonder if i can make of useful space where the empty area in the coffin will be, if anyone has ideas? I can either seal everything up as normal or trying to make a little floor storage access?

[snappergapper]

You do not need to have an access panel if done correct. I don't have one. less chance for water penetration. I would build a bulk head, cut the coffin lid to fit and make the back area storage with a hatch on top. You can raise the floor a bit and foam around the area for an insulated box as well. I would think a perfect spot for fold up net, bucket with cast-net, small cooler with frozen bait etc.

[Justin]

I thought about using the unused coffin space, and even contemplated a walk-in console head...but in the end, I preferred to glass the tank coffin down and just make the whole thing watertight.

I have enough storage.

[hunt-mor]

Maybe I will just make use of the livewell instead and completely seal the coffin back up.

A lot got done in the past 3 days. I took the coffin out and started digging the foam out underneath. The coffin was pretty easy to cut out, after grinding the gel coat off, a circular saw and sawzall took the coffin out in minutes. My angle grinder thats 20+ years old(older than me) decided to crap out while cutting and I wasnt messing around with my cordless grinder. After printing the coffin out I went to digging and cutting. When I get the pics up Ill add more info

[hunt-mor]

Heres some pictures from the past days.

Cutting the coffin out.



My buddy dean has been a huge help in this project helping out with the easy stuff that are time consuming. Here he is learning how to grind the gelcoat off with the sander.



half the coffin torn out. Took a little to figure out how to break the foam seal but was a easy step.



Coffin out completely



Digging more foam out!