Aquacraft twin outboard

[greenman407]

I saw this perfect little wooden outboard at the hobby store a while back and thought that it would be just the ticket for a quick on the water project. I already have just about everything that I will need to get it on the water. The good thing is that the hull comes pre-finished with a natural wood hull that you can paint if you like. I think that Ill leave it as is for now.

[greenman407]

The price was quite reasonable at $120.00 Ill need to strengthen the transom and install a alluminum transom cover plate to carry the two motors and there adjustable mounts. These K&B 3.5s I picked up off of ebay a couple of years back will provide the motivation. To keep this boat from prop walking so much Ill introduce a negative angle to the prop thrust line to keep more of the props in the water.

[greenman407]

Oh, and by the way, this boat is not made for twins. But, you know me, Im always trying to push it.

[greenman407]

Lets get moving. Whadaya say? To start with I cut two 1/8" x 1" alluminum flat bars 4 and 1/4" long. They will serve as the mounting plates. On top of them you can see the two adjustable outboard mounts. I will test mount the engines and hold them onto the transom to properly mark the req. mounting holes to get the engines at the right height so that the props will be where I want them in relation to the bottom of the hull. The mounts allow for some adjustment but you need to be in the ballpark first otherwise you wont have enough adjustment and in the right direction.

[greenman407]

Vibration and hull strength will be a problem. So, since this hull is held together with glue we will have to install some angle clips and some screws in the right places. In these two views you can see the engine mounting area and its supports. Inside the two vertical walls are where the fuel tank sits. What Im going to do is cut out the upper deck thats inside those walls so that I can get down to where they attach to the bottom skin. At five places Im going to strengthen those connections with some alluminum angle and stainless screws with lock nuts. After that we will reinstall the cutout piece or add a new one to restore the strength. You can see here from the bottom where the two uprights attach to the bottom at this doubler plate.

[greenman407]

In these two views you can see the overhang that we will have installing two motors on a one motor design hull. As we move along on this project we will see what we can do to disguise or minimize this.

[greenman407]

Out comes the Fantastic...Dremel maxicut. The only way to fly. Im going to remove the deck inside the two uprights. First I need to get rid of these wood blocks. Smooth as can be and then to cut along the inside and along the line.
I was quite disappointed to see that Aquacraft has used that cheap white styrofoam in my boat. After cleaning it all out of the general area I then measured for the alluminum angle that will be both epoxied and screwed into place. I will install it on the bottom and up the sides.

[greenman407]

In order to get the angle to fit like I wanted into the corner I had to cope the angle like so.
Then it was on to drilling out the motor mount plate and to then drill the transom.
In preperation for epoxying the angles, there backsides needed a cross hatched pattern cut into them for good adhesion.
I also took the liberty to change the factory motor mounts with some adjustable ones.
As you are reading this the epoxy is drying.

[greenman407]

Then I epoxyied in the angles and attached the double motor mount to the transom.

[greenman407]

Now, on to fuel issues. The factory tank is unsuitable because it only has two built in lines......and that wont work. So I turn to my usual Sullivan fuel tanks. I always like using a header tank in addition to the main. In this way you increase fuel capacity and you have the tank that you draw from directly at carburator level. Since height is at a premium, I cut out the deck using a combination of standard Dremel and Dremel Multi max. In this way there is now room for a 12 oz. RST style tank and a 2 oz. header tank on top. The cowl still fits.

[greenman407]

Ive been delayed waiting for a tubing bender that I ordered to come in to finish the fuel tank install. My other set got "Shanghied"(spelling,I think). I dont speak Chinese. Does it show?

[greenman407]

Got this neat tubing bender that makes short work of bending the brass fuel tubes without kinking. The 2 ounce tank was a simple matter of pushing three tubes down inside. Two of them will be fuel pickup, one for each engine. The other one will be fuel transfer from the bottom tank. The twelve ounce tank reqd. bending the exhaust pressure tubes at a 90 degree angle to have the open end terminate at the top of the tank. The other tube was attached to this hose and the weighted "klunk" at the end.

[greenman407]

Because of the limited room inside the hull as respects clearance for the fuel hoses coming out of the tank it became necessary to open up the area a little more so that I was assured that there would be no kinking of hoses. So I cut out the opening a little more. There........that looks better.

[greenman407]

With the cowling in place it looks like this. I think that it will work out fine. Now , the next task will be to get the steering hardware to work.

[greenman407]

Just a preliminary placement of the servos. The Futaba S3305 servo has a metal gear and a whopping 124 in. ozs. of torque. Itll be used for steering. Im not going to use cables for the steering. Im going to use one rod connected to one engine and then link the two engines together.