aerokirk's build

[Doozit20]

Great looking work you've done there. Its always nice to be able to sit and try to figure out what to do next and its hard to think of anything except...where can I start sliding this thing?? thats when you know your getting close. Oh on the exhaust, do you have a part number and a pic?

[aewrigh]

The part number is IH-1. Google "IH-1 muffler" and it comes up at several stores. Tractor supply carries them.

[aerokirk]

This past week was a productive one ... welded and installed the fuel tank/battery framework, instrument panel and I'm starting the rudder mounts. Started the exhaust system and will mount the mufflers shortly as well as the oil cooler. The mosquitos are so bad outside that I had to take the boat off the trailer and put it on the floor of my garage where it's bug free and much cooler. Good to see all the other build activity on the site !!!

[Doozit20]

Thanks Ill check out those mufflers. Builds looking good. See the finish line yet??? its right on the other side of that tall grass, just stay on the throttle and get r done lol

[aerokirk]

Rudders installed! On to exhaust headers and steering cable.

[Doozit20]

Is she crank ready?? I think you are going to love that longer prop. If I ever decide to go with a reduction I think im going longer prop with a little less pitch. I just think it will catch a lot of air and give you a higher top end. And with it being adjustable you can dial it in.

[aewrigh]

I was thinking of trying a different muffler....walker makes a 12 inch long case 1.5" in and out. Also going to mount the mufflers in the bottom probably so I can run a pretty good length of pipe after the muffler then exit through hull above the water line. Hopefully about all I will have is prop noise

[aerokirk]

Much as I'd like to crank it up now, I'm forcing myself to wait until I have the majority of the systems installed and operating. The desire to see it running is fueling my ambition to keep working and completing what I've started. It's frustrating to see the summer melting away and the build still going on but I keep telling myself that the final product will be worth the wait.

I'm at the point now where each day I seem to finish one task and I can see the light at the end of the tunnel. I realized how valuable detailed pictures are to future builders since many of my ideas came from others so I thought I'd post some details of my build:

bottom rudder support

muffler supports

front muffler support & clamp

top rudder connection

showing how front of cage connects to main frame - 1/2" tubing inside 5/8" tubing (easily removable)

[aerokirk]

Two more long days of fabricating ... finished the headers and exhaust system, oil radiator mounts, steering system and rudder installation. Next it's on to wiring, throttle and then .......first startup!!

[aerokirk]

Today was the day of the maiden voyage!!! I started the engine while on the trailer attached to my 4 wheeler and at half throttle it moved the whole rig forward. It ran so good I decided to launch it and when I tried to accelerate on the water the engine died. It would not run at anything over an idle and I'm suspecting that I may have a blockage somewhere in the carburetor or fuel line. As a result I had to put it back on the trailer and park it for the day. Oh well, some glitches are to be expected.

[aerokirk]

Update ... problem solved! Shortened the fuel line from tank to engine as I think it was getting air-locked and starving the engine of fuel. I launched the boat again and YEE-HAW!!!; the performance was awesome! Got up on plane quickly and then sped up until I thought to myself ... holy s**t am I going fast and just about that time I input rudder in the wrong direction (my first airboat was rigged opposite) and I spun out and went on a wild ride with the tail spinning all the way around and the bow submarining for a few seconds. I give the boat credit as it righted itself and away I went as if nothing had happened. I think I gave some fishermen a laugh though! After a bit of testing I gave my wife a ride around the lake and though it wouldn't plane in deep water, it did quickly in the shallows and then it maintained it even in deep water.
I believe Harbor Freight has an optical tach which I think I'll get in order to confirm my Faria tach reading as I think it might be reading a tad high. Other than that, my oil temp and pressure looked good and the boat performed beautifully ... it makes all the hours of build time so worth it! I love the Circle-S reduction drive!! The starter flings that prop around nicely. Noise level was very tolerable with the two blade Whirlwind and I've got an intercom system that I had left over from my aircraft when I upgraded it so I can now wire it into the airboat and use our Dave Clark headsets.

I'll have to get my hands on a Go-Pro and take a video of the finished rig a.s.a.p.

[Papee]

Enjoy the ride! My memory is not the best these days, are you using the stock carb? If you are it helps to drill the holes in the metering rod out. They are the first things that clog on the stock carb. The performance doesn't increase much but it does help with the dead spot and the clogs are not near as frequent. My uncle is coming up this week to run his boat for the first time so I should be getting to the new dual carb setup this weekend and hopefully be testing it soon. Keep an eye on your oil temp, I find that if you run long periods at a time it starts getting a bit high, I run an oil cooler on mine. With you running more rpms with the reduction drive you may see higher oil temps, mine runs about 180*.

Just looked back and seen that you do have an oil cooler.

[aerokirk]

Thanks for the info Papee ... Do you know what size drill you used to open your metering rod? My oil temp ran about 180 deg until I ran WOT for a spell, then it went to 200 so I eased off a bit. Still in break in period on the engine so I'm not running it hard yet. Glad to hear you're back on the dual carb project ... I know I won't put up with that dead spot too long before going to a better carb (or two).

[txriverrat]

Thats a good looking rig.
Ron

[aerokirk]

Thanks Ron! I can't begin to tell you how much fun it is .... I can't stay off of the thing! The rudders are working fine and it is totally controllable at all speeds. Today I'm working on my trailer installing side rails to keep it from sliding off sideways. Then I can take the boat to some of my favorite spots.

I'll bet you're anxious to get started ... one of the best fringe benefits to the building project is the fun of getting new tools. I am amazed at how many things I've found to fix around the house using my new spool gun

[Doozit20]

That first ride is always fun. Happy to see you get it going and you got your carb issue figured out. What kinda of numbers are you getting and pitch? Rpm of engine, ratio of reduction, and most important....how fast on gps does she go lol?? Congratulations

[aerokirk]

I still have not obtained a Go-Pro camera but I did manage to secure a short video of one of my runs thanks to my neighbor's cellphone camera

http://youtu.be/e4w7GmlZzvs

http://youtu.be/KH9X-KQUwM8

[aerokirk]

That first ride is always fun. Happy to see you get it going and you got your carb issue figured out. What kinda of numbers are you getting and pitch? Rpm of engine, ratio of reduction, and most important....how fast on gps does she go lol?? Congratulations

Got the first numbers today with my GPS ... measuring prop pitch three inches in from tips I've got the blades set at 12 degrees which is giving me max engine rpm of ~3200 to 3300 and a top speed (solo) of 31mph. Cruising at 2800rpm gives me a speed of 22 mph (solo). Didn't take speed readings with an adult passenger yet but I would estimate the speeds drop by about 5 mph or more.

The reduction drive is a 1.69:1

Not too happy with the stock carb and I don't think I'll put up with the acceleration flat spots for very long before I go to either a different carb or EFI if I can find a setup thats reasonably priced and tested.

[aewrigh]

Are you going to lessen pitch and crank those rpm's up a bit? 3600-3800?

[Corky]

Great looking rig.... Another question for you...Now that you're up and running is the boat as quiet as you'd hoped ??? Nice tone from those style mufflers ???