I'm building Coroplast EXTRA plane.i want to buy the engine . . .
total weight is 3kg. which one is best.My friend told OS 55. how about this . . . and tell me about ASP 52

underpowered, os 60 would be good, however i have seen people fly upto 5 kg aeroplane flown with a 0.52 engine, for an edge though 60 2 stroke will be good, 75 4S would be better

Would that be an Edge 540 profile? An OS 60 would be good or an ASP 75. My suggestion would be, try and shave off weight from where u can. Even 10 gms matter. I'm sure with some thinking u would be able to take off about 100 - 200 gms.

Waiting to see the plane in action.

Doc