Ok, I got the ap .09  running today. I'm prsently using a 1/2a fuel. 16% castor oil, 25% nitro. It runs. So far I cannot say how well. I'm using a tach but the readings I get are all over the place. Not sure if the tqach needs work or just batteries or ? who knows. But I have a 8,4, on it and it does run. I'm prolly going to switch the prop to something smaller and see how that acts. wish I had a propeller balancer on hand and a few 7" props. But right now I do not. Boy these AP props are sharp. Cut right through a cloth glove trying to start the sucker.

Even the Tee Dee .09 would not be happy with an 8" prop, it ran a 7x3.5 .   The AP engines are much happier reving up, so I expect that a 6x4 or 6x5 would be the best bet.  Recheck the instructions and go to the lower end of the prop sizes, especially for break-in.  Tee Dee engines produced a lot of torque to swing relatively large props, they were intended to pull free-flight models straight up.  Yes they would rev, but not like a modern Schneurle engine.

I cut down an Master airscrew 8-4 to about 7.25x4. I balanced it on a q'tip. OK,so it isn't the best way to do it but it's a rough balance. Put it on and the engine ran fairly well. Still needs more breaking in. But when it was running It will definitely pull the Akromaster. I'm sure of that.Maybe next week I'll get to try it.