The Retrol HM-01 Hit & Miss Engine: A Real Jewel
I built the Retrol HM-01 hit & miss engine. The assembly instructions were excellent. I used the PDF version of the assembly manual on my computer while I put it together. The parts were well made. After adjusting the Ignition Trigger electrodes and the mixer [carburetor] it started up and ran the way a real engine does. The only thing that I had to keep checking is that the flywheels loosened on the crankshaft and needed to be retightened several times. Possibly an extra screw is needed for each of the brass bushings [4 instead of 3] to keep it tight. There were no instructions for installing the spark plug boot. I couldn't determine how to attach the spark plug wire to the spark plug when using the boot so I adapted a crimp-type spade connector to attach to the spark plug.