Rodrigo,
Hand launching twin engine airplanes can be pretty exciting. I have had two combat twins - a DeHavilland Hornet, and a FW189. I could not self launch either one and needed a helper to get them airborne.

The best method for launching either of them was to hold the plane by the booms or fuse, just behind the wing, overhead then give it a toss into the wind at a relatively flat angle.

Launching into a headwind will help a lot on your first few tries.

If your launch partner throws the plane too hard it can pitch up and stall or it will lose fuel draw for a moment and stall.

Twins need to have rock solid engine reliability. Aft first I tried to sync the engines to each other. This did not work. Instead start one engine, peak it out, then back off 300-500 rpm. Shut it down and do the same with the other. Once satisfied that they are both set properly fuel them up and start them for flight.

Good luck. Photos of my scale twins and those of some others can be seen on www.georgiacombt.com in the Scale planes section.