RE: Sig 1/4scale C/W Cub build
Right now Hobby People has the Magnum 91 4 stroke on sale for $149. That is an excellent price. I own both Saitos and Magnums, and the Magnum 4 strokes are a sweet running engine. I actually use Magnums on my Scale Planes cause I think they have a better scale sound, and I use the Saitos on my Aerobatic Planes cause they got that one of a kind Saito Sound, plus a little extra power. The Magnums are an extremely dependable engine, and the break-in process is much shorter than that of a Saito.
I have been leaning more towards usiing the Magnum 120 in my c/w 1/4 scale cub, but the 91 would probally fly it around scale like. With the Plane being a clipped wing, I do want mine to have enough power to do a few basic aerobatics, and this is why I would probally go for the 120.