We are routinely asked in detail what challenges we faced while building the Bowfishing Madness Boat. I decided to write a page and include pictures on just some of the processes necessary to build a top notch fan boat.
The Bowfishing Madness boat is 18' 4" long and 6' 8" wide. The boat was built in Arkansas at the Excel boat manufacturing company. Disaster struck when a tornado stormed through Clinton Arkansas destroying the entire factory. The company is now out of business. Building a fan boat and doing it right takes a lot of time and skill. I have a best friend that just happens to be a fabricating expert. His skills proved to be a critical asset in building this fan setup. Together we were able to put our thoughts together and build an awsome bowfishing boat. I also took advantage of the internet and used the expertise of many current fan boat owners. They all made building this boat a less daunting task. Thank you!
Below are two pictures of the boat during it's building phase at the plant:
I purchased the boat not long after it was built in 2007. The boat already had the lights installed and turn-handle cable steering installed on the front for the fan setup that was soon to come.
The pedestal that holds an engine was already there but the fan engine was not installed yet. The boat did have a 150 HP Evinrude.
My first goal was to focus on building a fan engine for the boat. After much discussion with experienced fan boat owners and research online I decided to go with a 35 hp Vanguard Briggs & Stratton Engine.
Next I had to decide which prop would best mate with this engine setup. I chose a 52" Powerfin adjustable pitch prop. This prop would obviously not fit on the shaft of the engine without a custom hub designed to fit both the shaft and the prop hub.
I could go into a lot of detail on the many different ways to install this prop on the engine but for now I will give you the basics. Many people will mount their prop directly to the hub and then mount the hub to the front of the shaft since the hole in the hub on the prop is not large enough to go over the shaft. We decided to enlarge this hole and slide the prop back as far as possible in an effort to cause less strain on the shaft of the engine.
The Vanguard engines come with their own fuel pump. However these pumps are not designed to suck fuel from any distance. Due to this we had to purchase an additional fuel pump in order to be able to pull fuel from the fuel tank on the boat up to the Vanguard engine. I chose a Holley Red fuel pump. There are cheaper fuel pumps out there. However I would rather pay a little more for a reliable pump. The Holley Red's received the least negative feedback during my research.
I would have like to have tied a fuel line from the Vanguard engine into the boat fuel tank. Can't do that since the boat fuel tank is an oil/fuel mixture. Due to that I purchased a 9 gallon external tank. And we had to devise a way to hold the fuel tank in place. My buddy fabricated some brackets to hold the fuel tank and the generator in place. I can run throughout the night with the Vanguard engine and will only use maybe 4 gallons of fuel.
The Holley Red fuel pump creates too much pressure for the Vanguard to handle. To resolve this I tied in a fuel pressure regulator and a fuel pressure gauge on the Vanguard to adjust and monitor the fuel pressure. This setup seems to run best around 2-3 psi. I also installed an additional fuel filter after the pressure regulator connection and before the engine. Of course a bracket had to be made to hold the pressure regulator.
In order for the shroud to fit flush against the engine we had to custom build a set of exhaust pipes for the Vanguard. My fabricator buddy built an excellent set of pipes and custom machined the ends to perfectly fit the exhaust and the engine.
Since the muffler rises above the engine braces had to be built in order to hold the exhaust firmly in place.
Another necessary piece was devising a way to work the throttle from the front of the boat. Teleflex throttle cable was used to reach from the front of the boat to the back of the boat. Then you simply connect cable ends to the engine and to the throttle handle on the front of the boat.
And of course the shroud will need to fit precisely. We covered one side with expanded metal and left the other side of the shroud open. We had to make a plate to custom fit the shroud to the Vanguard engine. Notice the plate on the engine shaft:
When I first purchased the boat it did have a steering pole up front that you actually turn in order to rotate the fan. This setup uses a series of pullies and a drum at the bottom of the steering pole and on the bottom of the pedestal. This system works fine. However when customers are on the boat I realized that this setup will bump into the customers when turning the steering pole sharply. I decided that a push/pull pole would be more practical in this situation. You will have to sacrifice a bit more effort to turn. You will need to experiment with different sprocket sizes to get the best turning radius and the least tension to turn the fan engine.
We started out by removing the pedestal and all of the pullies and cables from the boat. Then we did a few mock setups until we came up with a plan that we liked. My buddy got busy on the machining and design side of things. I began removing everything and drilling and doing whatever was necessary to install our design. I was able to order different sized sprockets from McMaster Carr. I purchased three different sprocket sizes in an effort to come up with a system that will allow me to turn 180 degrees on one side and 90 degrees on the other side. That way I was able to back the boat up when necessary. My sprocket configuration to get to the turn radius that I wanted without being too difficult to push and pull the steering pole is: One 20.1 sprocket and one 60.1 sprocket with a 40b chain.
Bearings bearings everywhere! We also decided to change the shaft the supports and rotates the engine to a more precise fit. In doing so all of the bearings needed to be replaced. So we removed the original shaft. Then got our hands on another shaft. The new shaft and bearings allowed for little to no play on the shaft which in turn made a difference on the amount of vibration that can be felt sometimes when turning the fan. My buddy also devised a tension adjuster to keep the chain on the sprocket tight.
After we completed the pedestal and sprocket install we had to focus on the push pole steering up front. We started out with a mock up. Then I ordered a solid stainless pole from McMaster Carr to use for the steering pole. We had to decide what size hole to cut into the floor. Definitely didn't want to big of a hole. My intentions were to keep this as clean and professional looking as possible. Everything had to be precise. One of the most frustrating task is squeezing up under the deck of the boat to perform the work on the steering and wire pulling.
We had to cut a plate to house the bearings for the steering pole. After designing and coordinating and figuring we finally had an excellent push/pull steering system. The airline cable was installed and everything functioned as planned. Once every piece was put in place the easy part was all that was left for the steering... the paint. Notice the welds on the first picture below.
A box to house the switch and wires up front had to be fabricated. My buddy jumped on the task of fabricating a switch box.
He did an excellent job! At first I used a push button to start the engine and a kill switch to kill the engine. This worked flawlessly. However after the first year I realized that I had grown weary of having to walk to the back of the boat and turn the key switch to auxilary, and then go to the front of the boat to press the starter button in order to start the fan engine. I decided to use a key switch up front for starting and killing the engine. I disconnected the switch on the Vanguard and tied the wires into the switch up front. This was much better than the push button switch. Now the only reason to have to physically touch the fan engine is the choke. If it is cold we usually have to choke the engine the first time it starts.
This boat has removable panels that made running the wires easy in the middle of the boat. Running the wires from the console and up under the dry box to the back of the boat proved challenging.
Working on the boat in the winter will make you appreciate your garage! Even though I could not get the entire boat in the garage unless I removed the fan engine and pedestal.
I decided to purchase and install a dual battery gauge after growing tired of always wondering how much juice remained in the batteries. This was a small addition yet well worth the money. Now I can better judge the amount of time left on the batteries for the auxilary powered items.
This boat will draft in 7-8 inches of water. She will cruise through thick foliage (bushes and grass) with ease. We can get into places that many boats would not dare try. All of the information mentioned above is only a small piece of what went into designing and building the Bowfishing Madness boat. This boat has been custom designed from the ground up for bowfishing. She even proved to function perfectly as an alligator hunting boat.
After many hours of work and many many dollars were spent, I did not want my investment to sit out in the weather. The final task was to build a home for the Bowfishing Madness boat.