Trial #2 Before starting this trial, I changed a few things. First off, I replaced the problematic speed controller with another one. The new speed controller does not have reverse but will easily handle the current. I also ended up changing the motor. I found that the brushes on the motor were worn out and the comm looked a little burnt. I'm guessing this happened when I picked up some weeds in the prop during the first test. The comm just needed some polishing but I did not have the right replacements brushes so I changed the motor with an old stocker from my junk drawer. The new motor works fine but is a dog, it is so weak that I can't even measure it on my dyno. |  |
| The test lake was much clearer this time around so I did not have to clean the prop hardly at all. |  |
The replacement motor makes the boat a lot slower then during the first trial. The speed was down to around 10-15 mph. | 
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With the weaker motor, adjusting the outboard motor angle made no difference on how the boat ran. | 
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| The motor sounded like it was not turning many rpm's. A smaller prop is probably in order. |  |
| I was surprised by how quickly the batteries were used up. I expected much more run time with a stock motor. I investigated and found that the end bell bushing of the motor was scorching hot but the brushes were just warm. It turned out that I had installed the motor in the outboard incorrectly. The motor fits into a shaft with a gear on it. The motor and shaft are attached with a collar. The collar should be just tight enough so that the shaft rotates with the motor without slipping. The motor should be able to move up and down within the shaft. In fact, without loosening the collar, you should be able to remove the motor from the shaft. I had it too tight and the motor bearing was absorbing all of the gear load causing it to overheat. |  |
| Here you can see the boat leaning while going into a turn. I learned that this is being caused by the shape of the hull. The sides of the hull are at a 90 degree angle to the bottom. This causes it to catch in the water. The sides really should be at an angle which would channel the water under the hull |  |
| Even though the lake was much clearer, I still managed to get weeds in the prop. I noticed that outboards seem to be bad about this. |  |
Trial #2 Conclusion The speed controller worked but the boat was just too slow with the motor I put on it. Also, I will have to be careful on how I install the motor so I do not cause the bearing to overheat. The prop seems to be too large and is bogging the motor down. I plan on changing the motor to a more powerful one and going with a smaller propeller on the next trial. I think this will give me the speed I want without overheating the motor. |  |
