Yep, the new OS 56 FS-A is really powerful. The advertisements
claim an additional 20% hp over the previous generation OS 52 FS,
and I don't doubt it. With the OS 52 I was using Powermaster YS 20/20
fuel (20% nitro). I always used that fuel, no matter the conditions
and it always used the same amount. With the 56 I have cut down
the nitro to about 15%. The motor just ran too hard with the 20%
nitro.
The prop is slightly bigger. With the 52 I used a 13 x 4 Eather 3 blade
that was cut down to 11.75" and repitched to about 5.5. With the 56 I'm
using a 12 x 4 Eather 3 blade repitched to about 6. I have 2 other props
to try out that are a bit longer, but haven't had a chance to yet.
The motor runs consistenly throughout the pattern, just as the 52
always does. It's pretty much set it and forget it.
Later, Steve