ORIGINAL: bigtim
in my Hangar-9 mustang which is about the same size I run a OS91 surpass its a fine engine for that size plane, a saito 91- 100 be a good size engine as well depending on the weight,for the lighter ARF mustangs 7-8lbs, the engine would be a great fit.
for a kit build like a Top Flight then a OS 120 or a saito125 might be a better choice since they tend to come in a bit heavy 10-12lbs.
my H-9 is a little over 8lbs
Thank's for the input guys. I was pretty much on the same track. Now it just boils down to making a choice. But, all of your arguments definately helped.