Two stroke versus a four stroke – which is best for a beginner?
Just had a look at the instruction manual for the Magnum 91 online, Hobby People have it available.
To break this engine in you're supposed to use a 14x6!
You will not be able to fly the trainer with this size prop on it!
On the 65LA you use 12x6... I'm still using the 12x6 and it flies the plane very well.... at some point I might move to a 12x7 or 12x8 but it's not necessary...