I've got Senior from a kit. It has an OS 91 four stroke on it with a 15X8 MAS prop. I just had it out today as a matter of fact. I love this combo. I had a 72 on it for a while and that worked well also. I've got all my servos up in the fuse and didn't have to add any weight to the rear, just shuffle the batteries around a little. I'll fly just a click or two off of idle but it'll pull like a tractor if I want it to. You'll learn a lot from a Senior if you'll take the time to get to know one. I'm sure you'll enjoy yours.