Tank placement

[fishbuster]

Redoing a 20' Dusky with a Yamaha 200 HPDI (I know not a seacraft) With a bracket and fixing to install a 100 gallon fuel tank and was wondering if i can get yalls 2 cents.

Originally the boat came with a 60 gallon fuel tank but want to increase the fuel tank size to a 100 gallons.

The new fuel tank is 72" L x 30" W x 10" H.

The old fuel tank was 37" L x 33" w x 11" H next to the stringers and 16" H in the V.

Some people was mentioning just to mount it in the original location just have the tank go forward from there. The original location was 48" from the transom.

I know putting the boat in the water and start putting weight in the boat would be the best option but i would have to mount the bracket but still have to paint the boat. But if thats what it takes thats what i would do.

But prior to tearing the boat up the boat sat stern heavy but also had a lot of wet foam, stringers, and transom. And a heavy dusky drive.

I replaced the transom with coosa and replacing the stringers with sandwiched 3/4" plywood. also have a hermco bracket that supposedly has 800 lbs floatation (i know doesnt matter when on plane). The HPDI weighs a tad under 500 lbs.

Also planning on putting a fish box up front of the boat and that would account for 200-400 lbs. Was thinking about measuring center line of the boat and moving the tanks center alittle under 2 foot beyond that. What would yall do if it were your boat?

Thanks
Randy

[Wildman]

I have never seen a boat that didnt benefit from moving the tank forward. I removed my fish box, moved it to the rear (under the leaning post) and slid the tanks forward in my boat. I also am adding a double hermco bracket.

[fishbuster]

Thanks wildman. Right now I am just trying to find where the optimal place to put the fuel tank is. I am wanting to move it forward as this boat was already stern heavy. But with the bigger fuel tank it will already have weight forward.

[FELLOW-SHIP]

Hi Fishbuster;

I would first suggest talking to people who know Dusky’s as much as people on this board know Seacraft’s. They would have a better insight on your boat.

But if I had to guess and I don’t like guessing not knowing your boat I would think somewhere around where the back of your leaning post seat going forward to somewhere in front of the CC. If the stern of your tank is close to the bilge area of your boat you probably need to move it forward.

I went from a 70” Long 100 gal tank to a 84” long 120 gal tank. I also moved my tank forward approx 12”. By doing this and some other things I redistributed the center balance line of my boat approx 18” forward. So now I usually don’t use my trim tabs for bow to stern trim in average sea conditions I just usually use them for port and starboard listing due to crews beer belly weight and which side of the boat they are standing drinking their suds.



FellowShip

………………………….

Just for the Grins

Official 23’ SF Antique Classic SeaCraft Owner

[gofastsandman]

You really need it set up as she will run. Carl Moesly had the center line of the tank directly over the cg of the boat.

That will be a challenge for you.