hi, i just assembled a zen-50 and just did 4 flights on it today. i've fitted it with a 50 SX n the standard muffler coming out of the side. I dont even use nitro. Firstly, the retracts are a nuisance. Secondly, in knife edge my zen falls towards the canopy, n big time! secondly , with my engine running a bolly 11.5x6 prop, there just doesnt seem to be enough power for the plane. U dont feel safe flyin the machine with minimal power. WHat do i do? need help!