OS .25 FP Prop

On a stock OS.25FP, mounted on a MEDIC,would a BY&O 9-5 be a good choice of prop?

The prop that you want to use is an APC 9x4 if your engine is stock. The rework version can use the wood 9x5-9x6 for the 4-2-4 break. I use the 9x4 zinnger at 10,400 and get good results. The plane must be light and have a good control system. The FP-25 can put out more power then the Fox .35 and should not be runed the same as the Fox. The FP-25 should use less fuel and less castor then the Fox. "Sig champion 10" is a good fuel for this engine. Also use a HOT plug. scott

>On a stock OS.25FP, mounted on
>a MEDIC,would a BY&O 9-5
>be a good choice of
>prop?

I don't have much BY&O experience, but we tried a 10-3 on Bob Hazle's 25FP Twister at the NATS last year and it went something like 7 second laps at a two-stroke!

The best setup for the Medic that we've tried so far is a 9-4 Tornado Magnum, with a Bru-Line Fine air filter. A 10-4 will work,too. The APC 9-4 will work, too. 5" tends to be a little fast.

If you have a set, I'd be very interested in the results from the BY&O 10-3, 10-4 and 10-5 with constant medium 2-stroke in level flight.

A well-built Medic/20 or 25FP is a very potent little machine. I was VERY impressed with the one Bob Hazle built, once we got the trim sorted out.