While perusing a box filled with miscellaneous old items at a local garage sale, I spotted this Herkimer OK CO2 motor buried under door hinges, bags of nails, and light bulbs. It was pretty dirty, but it seemed fine otherwise. Half the propeller was missing, so I assume when it broke, that was on the motor's last flight. The motor had been mounted to the still-attached plywood firewall with three small brads! Price" $1.
After carefully disassembling the OK CO2 motor, it was soaked overnight in Evapo-Rust, an excellent water-soluble, non-toxic rust remover which I have used often. It cleaned up very nicely. A few drops of Cox after-run motor oil was used when reassembling the motor. I do not have a CO2 cylinder small enough to fit into the holder, so I have not been able to run it yet.
According to advertisements, the displacement of the Herkimer OK CO2 motor is 0.0178 in3., which rounds up to 0.02 in3.
For more things CO2, see the "Fizz-Wizz" article from the March 1962 American Modeler and the "Push-Air CO2-Powered Free-Flight" article from the February 1970 American Aircraft Modeler. You might also be interested in my DP-03 CO2 motor, with a video of it running.
Herkimer OK CO2 Motor
Herkimer OK CO2 Motor Disassembled Crankcase Top View
Herkimer OK CO2 Motor Advertisement
Herkimer OK CO2 Motor Parts Breakdown
Herkimer OK CO2 Motor Box Instructions
Posted August 24, 2019