i have used both the YS 140 sport and the OS 160fx and the OS was much stronger and loves 10% nitro. the 73" yak is way better with the fuel tank centered on the c/g. very small changes in c/g drastically changes the attitude of the plane. i have also used the Perry pump on several different models without any problems, just read and follow their instructions. i have heard very good thinks about the cline system but have not tried one yet. just my take on it, good luck with what ever you decide to go with. keep us posted

randy racer