I've had one of these since the beginning that had a bad piston/cylinder set.  I never have found the parts to restore that one but after buying several more off Ebay I think I've finally got a few that should run. 

Anyone that has experience with these engines want to tell me how I should set them up, and how I should run them?  Props?  Fuel capacity required for a typical pattern? etc...

Thanks in advance.

PS: A 19 is almost a 20... so I could use 10% nitro, 2030 muffler, APC 9x4 prop, and tach it to 11,300 rpm... Right?    I am just kidding. 

My original one was a .201, which was actually a .19, but stamped .201 on the case for "B" Free Flight use. Duke was devious.

I first flew this engine on a Ramrod 600 with a TF nylon 10-3.5 and MissleMist. I found it would climb at a rather subdued rate with this prop. Changed to a 9-4, and it really improved the climb and power pattern a lot. Later, I came onto a screaming deal on a Veco Warrior for $10, and I put the .201 on it. I knew little about stunt, but had flown a lot of combat, and knew what I wanted. Slow, steady speed. The 10-3.5 worked well, tho probably a wood version clipped a half inch would have been better. I flew it on 60' .010" solids.

It was tailheavy, and would do very sharp corners, so before long, I was doing square vertical 8's. Didn't know there was no such thing in the pattern, and really didn't care. The 3 bolt Fox .19, IMO, is the best all around engine Fox made, tho a .201 or .25 would have been just fine. I currently have one .19 in good shape that is intended for a Carl Goldberg "Cumumulus" FF gassie. Cool design....
   Steve