As stated in the title, I have a Seagull Edge 540 (60 size). Currently I have a Saito 100 in it and I am not happy with the power. It flies fine, but is under powered. It takes full throttle to hover, and even then she wants to fall out of the sky. The prop is a Vess 14x6. I was thinking about a 26cc gasser, but one, don't know if it will fit in the cowl, and two, is it any stronger than the 100? Should I go with a 120 four stroker? I am open to suggestions.

The prop for 3D on the Saito 100 is a 15x6 Xoar or MAS S2. That might get you a pound more thrust

The 120 Saito weighs an ounce more than the current Saito 180.
Next logical step is the 125 Saito with a 16x6. Gas adds a lot of weight which is what you are trying to overcome.

Hello Cowboy Chris,

I have a YS110S fixed to a Seagull Edge 540 60; terrific combination. I had to put a 15 X6 APC prop on engine to slow down the airplane a bit; even then, do most of flying at half-throttle. Verticals at full throttle are literally "out-of-sight." I very much enjoy this airplane, and think it great value for the money. Hope these comments are helpful in ensuring you enjoy your Seagull Edge 540.

Happy flying!
Ken

I mis-typed earlier - the prop I am using is a 15x6 Vess (not a 14x6). Does a YS-110 really put out that much more power than a Saito 100? I am willing to try something new, but don't want to plop down hundreds of $'s for a marginal improvement. I want to be able to hover near the ground and be able to pull out of it when I get in trouble.

YS110 is very slightly more power than a Saito 125 and at the same time slightly more temperamental.
The Saito weighs 2 oz. less and would be my choice for that airframe.

A friend of mine had one of these with a OS 120AX and it was balistic! I am a big fan of 4 strokes but this was a better combo than you could get with any 4 stroke.