RE: Top Flite B-25 ARF (Tecnical, tips, suggestions)
For those who concerning about the OS 81 FS-A installation, take a look at my setting. Just use the template of OS FS70 in the manual and you will be fine. I change the exhaust header to the curve one that come with the FS70II and it will fit in the cutout like a glove. And the power of OS FS81 is so much more compare to FS70 surpass II, I use MA 13x6 3-blades at 9800 rpm.