Sometimes the gas solenoid will stick. Rapping on it with a screwdriver might work. Or maybe it is shot and needs replacement.

My Rafale was converted from OS 91 power using the Avonds conversion kit for RAM 500. In ducted fan form, it seemed a good deal tamer, maybe because it was a bit lighter. In turbine form, it flies well if you set it up right. It does go faster with a turbine, but not a whole lot. I think the inlets are really draggy and make the top speed less that it could be. Not that I am complaining: it goes fast enough.

Make sure the aileron deflection is no more than 1/4" up and down, since it is extremely sensitive in roll.

Elevator should be about 5/8" or maybe even 3/4" up and down, since it is not so sensitive in pitch.

These settings are just about what Avonds recommends. A little expo on aileron may help too. I say "aileron" and "elevator" when of course the plane has elevons.

Good luck with yours. It is a very pretty plane and looks great in the air. And from reading my original post, you know to keep the power up in the turns. It slows down amazingly fast in a turn.