What Ken just explained is exactley where I am now. Last year was my first year in IMAC and I flew with a EF 87" Yak with a Brison 3.2. It was an amazing plane to fly but it was too small and I have now moved to a 40% Carden for this year. It is a huge jump but I am excited but also scared at the same time. I could have made a slower transition but I decided the price jump from 50cc to 150cc was just a little larger than the jump to 100cc, so I went to the 150cc size. I also got a steal on a 40% Carden that I have completely gutted and recovered and will have ready in a month. Good Luck and wish me well too...