The asp91 will not hover this plane even on 30% nitro as well as getting it as light as mine. When I ran my saito 100 on 15% on this plane it was terrible, it only became fun when I started using 30%... Don't cheap out on the engine. If you are going to go with a 4 cycle go with a 120 size or bigger motor. This plane flies best the lightest you can get it and that includes a light motor with a lot of power, You can't beat the 120ax for this. I have a magnum 91 (same as the asp 91), ran it in my twist 60 was very let down by the power. replaced it with the saito 100, BIG differance! But remeber the Saito 100 is good in this plane if you want to run higher nitro (last I checked $37/gallon in canada)

Don't get me wrong the asp91 is probably a good engine but it is something that I would put on a 40 size plane... Besides magnums and other knock off engines like the asp yer looking at are heavy. My magnum 1.20 is 34 oz (2.1 pounds!) These are great for war birds not extras.

Best bang forthebuck, go with the 120ax u won't be sorry... Or even the new os 95ax.

ASP FS91AR Four Stroke Glow Engine
Weight: 640g (640 g = 22.5753 oz)

OS120ax ( http://www.greathobbies.com/producti...od_id=OSM120AX )
Weight: 22.82 oz