Cox Olympic .15

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    I finally found one reasonable in nice shape. Not mint but nice. Super compression and smooth bearings. Has anyone run and used one of these in FF? I have a Slow Worm 432 partial kit from Campbell’s. I also have a good Sportsman .15.


    > Has anyone run and used one of these in FF?

    Not since the ’60s! As far as I recall it handled very well, other than the common reedvalve symptom of occasionally starting and running backwards …. I switched it into a model previously flown with a Webra Mach 1 diesel (same bolt holes) .. pulled the wings off, which might say something ….


    I have a couple of Olympics. The last one was in great shape and flew it one season on a Ramrod 600. A little too much model for the engine.

    But I stopped using it because after a short time there were aluminum shavings in the crankcase from the engine running backwards too frequently. Anyhow the crankpin shaves off the backplate and pretty soon the reed retainer falls out because of the loss of material.

    Anyhow it is a good running engine for awhile.

    I flip started it, so it would frequently run backwards. I think you would find the same problem using a starter with the starter pressing the crankshaft rearward.

    Stick with the greenheads or Max engines in Nos for this size.

    I will be bringing a bunch of excellent green heads to the NATS for the swap meet. If you need any before that, let me know, and I will send you a list.


    I,ve had an Olympic in a JaysBird 400 for 6 years. I use my 1/2A starter and don’t have a problem with backwards starts. I start it with a prime from the bladder. The Max111 would probably out-pull it, but it is what I had when I built the plane.

    Mounting the little beastie is the biggest issue.


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