PipeMajor re your post about the 20FP/S.

I've just inherited a used loop scavenged MAX 20. I'm going to bench run it this afternoon and tach it to check out its condition. Internals look good and like it's had not much use and a relatively easy life. Compression is solid for a cross-flow motor. It should be around the same (light) weight as your O.S. 20 FPS if lesser in terms of peak power output -although an extra head shim and 10% nitro should assist that. I haven't got an APC 9x4 to test but I'm thinking that'll be around the perfect design and size prop for the MAX 20 on a TF Flight Streak ARF.

If known can you advise what yours tachs (ground); and what length and gauge lines are you using with that combo? I 'm thinking I can get away with 60' if I go .012.