and I found an old Johnson 10 horsepower motor for a donor lower unit I
pulled off the power head and installed the Etek motor. Here's the
unit. A 1/2 inch aluminum adapter plate was fabricated to accept the top
of the lower unit. Another 1/2 inch plate was made to fit the mount
of the motor and a special coupling was machined to adapt the output
of the motor to the drive shaft of the lower unit. A lot of the former
underwater exhaust was sawed off and the exposed areas was filled with
epoxy putty. The rear portion of the cavitation plate has been removed
and a prop off of an 18 horse motor has been fitted."
"For initial testing the motor is being run on 12 volts. A swing arm is attached to the test tank and a spring scale is attached to the end of the swing arm. As different power configurations are tried and different props are tried, readings will be taken to try and arrive at an optimum combination."
"The initial test runs on a boat look promising. For this first test, I scrounged up three 12 volt batteries of unknown quality connected them in series for 36 volts and used a solenoid to connect to the motor. The start up torque was incredible. You really have to be hanging on to the tiller when contact is made. In the pictures above, my Diablo is being used as the test bed. It's fifteen feet long and has a five foot beam. The hull weighs 245 pounds and as tested with batteries and driver the weight was probably about 650 pounds. An upstream and downstream pass was made while recording speed with a GPS. The 2 way average was 5.7 mph. Just a little bit more and it might have gone on plane."