I am building a CG Extra 300 and am planning to install a 2 stroke OS .91 FX. I live in Mexico City and my flying field is above 8,000 feet so we need extra power. I have read that many install in this plane a 1.08 2 stroke. Will my plane be under powered?
I already have the OS .91 but I can trade it for another engine. Will someone recommend a larger engine. Is it better in this plane to use a four stroke? Maybe a Saito 150? How about a Supertigre 2300 (1.40 cubic inch)?
Thanks for any ideas

Hey Cafusin,

I built a CG Extra several years ago and put the Saito 150 up front. I also used the standard servo tray and ended up adding weights to the tail for CG. If you go with the 150, I would consider adjusting the location of the elevator/rudder servos to the rear of the plane.

Good luck, its a great bird.

Hello; When I first built my GB Extra, I put a Magnum 65 SE in it, lots of power but too thirsty for fuel. I then put an OS 91 FS in it, that worked pretty good, but I (mistakenly) listened to the other fellows at the field and put a Saito 120 in it. This flew it with lots of authority but made it that little bit heavier, and took away some of the floatability that I liked with the 91.

I fly at sea level here and can't imagine what it is like to fly at 8000 feet altitude, I think you'll be okay with most any 120 or with a Saito 100. I know that it is the popular thing to over-power planes, but I preferred mine with the 91.