Medallion .049 Exhaust Throttle Muffler RC Conversion

Today, I mounted the Kamtechnik radial mount for my Medallion .049 engine. When tightened, it precisely aligned itself where I can insert #2 sheet metal screws evenly spaced into a plywood bulkhead. However, I did notice something, and I think this may have to do how through time, various .049 engine crankcases have their backplate threads cut a little different than others. This is why he drilled so many holes (12 total) in the mount area, so one could successfully mount the engine no matter what Tee Dee or Medallion one owns.

However in my case, once it tightened it up, the two screw holes are slightly blocked by the crankcase, so one would screw the backplate in place, but not snugged up yet, insert the two top screws, then tighten the back down. There is sufficient room for a small screwdriver or Allen wren to snug it down, just not enough for screw to cleanly be inserted into the mount hole if back it tightened down.

It is just one of the minor sacrifices in having a mount compact enough to fit nearly every fuselage firewall situation. Otherwise, the Kamtechnik backplate mount is an extremely well made precision part that perfectly replaces the stock backplate and provides an excellent solution for a convenient and compact mount for these Cox front venturi engines. I also bought one for my .09 Medallion muffled R/C.



I attempted to remove the cylinder, so I could mount the later non-SPI cylinder and throttle sleeve muffler, but the cylinder is on very tight. I will have to partially disassemble to remove the plastic venturi carb body, then gently apply heat from my propane torch. This should swell the aluminum a tad enough so cylinder then unscrews easily.

I plan to salvage and reuse the Babe Bee style single bypass SPI cylinder and piston after resetting the socket, on my "Bumble Bee" custom yellow powder coat, cast crankcase and 8 cc non-stunt plastic venturi tank that recently arrived from Bernie. With his brass prop thrust plate or Killer Bee thin stainless thrust plate washer (have both), I can use this "Bumble Bee" engine as a pusher, too.