What a blast from the past, I bought a Arden .099 must have been about 1947 or so. Flew it in a little free flight model for a while, complete with coil, condensor (capacitor to you young fellows) and two AA cells. It did not have a needle valve but relied on varying the air intake for mixture control with the little lever you can see in the video. I bought a glow plug about 1948 and put the coil and stuff in the drawer where I believe it still resides. The engine powered the first RC plane I built about 1954, a Jasco Electra. Complete with single hard tube receiver, Sigma 4F relay, and a Babcock rubber powered escapement. I considered a successful flight was one where I landed on the same 50 acre field that I launched it from. Great to see that old engine again............RJ