Very, very nice set up. I have been installing starters on my Quadra and Zenoah engines for years. About anything with a rear shaft can be fit with a starter. I currently have a Ziroli Skyraider powered with a G62 with my starter installed and operating very well. There is nothing better that setting the choke, cranking the engine until it pops, opening the choke, hit the starter and she fires up. And yes I have restarted one of my engines in flight.

What you have done takes the process to a whole new level by machining and installing a starter on the DLE111 (no rear shaft). Watching the video, I assume you are using a Torington Clutch bearing on the main engine shaft that allows the starter gear to engage the engine and then release when the engine starts. The backlash you hear when the engine is shut down is the engine driving the gear train backwards. This happens with my starters and you are right, there is no damage to the system. I like the use of the outrunner motor to drive the system. Much more efficent!

I hope you continue to develop the starter and make it available for sale. I would buy one right now for my DLE111 powered 1/3 scale Bird Dog.