UMS Evolution Radial Care and Operation
Last April at the Toledo Show I was walking near the Horizon hobby area and spotted a bunch of radial engines that looked like my UMS Seidel engines. I said "hey I have all the glow versions of these engines". I met Pete Bergstrom who is overseeing the import and development of these engines! Great, now there will be a place where we can get parts and support in the US. These engines are said to be available in November and will be branded under the Evolution label. The displacements will be increased from 70 cc and 90 cc to 77 and 99 cc respectively.
My name is Tom Maxam and I have been modeling since around 12 years old. I am currently 52 so, wow around 40 years. I ran gas and electric boats including competition electric with Ed Hughey as a mentor. Within a year of starting RC airplanes I went totally for the 4 cycle engines. I am up to 43 of them including six radials! I have a Hangar 9 corsair with 400 flights on it powered with a Saito 90 R3. I also have a 50cc Yak 55SP powered with a Saito 325 R5. When the UMS Seidels came out I had to have one. The first one was the 7-70 which I bench ran extensively to learn how to tune it and understand the quirks. Later I acquired a 9-90 and finally the 7-35. I soon discovered these are not paperweights but reliable solid engines that can be flown heavily. I am also quite experienced with the Moki 150 and 215 cc radials and have learned how to make them run well.
The goal of this thread is to discuss all aspects of the care and operation of these engines to help others realize success. Topics will include fuel, Ignition, tuning, valve adjusting, cooling, prop selection, preventing hydraulic lock, fuel pressure tapping and after run oil and corrosion protection. Pete Bergstrom from Horizon has agreed to occasionally contribute to this thread.
I currently have the 7-70 in a 91 inch corsair. It weighs 20 pounds and flies magnificently. The 9-90 is in a restored Robin Hood 99. Both planes have over 50 flights. The engines are showing no wear.