My two cents on powering a senior telemaster is that this airplane has been arouind for a long long time. It's a very good design or it wouldn't have survived this long in the marketplace, but you have to remember that when it was designed, it was a .60 size airplane, which at that time meant a non schneurle ported K&B or something similar. That's about the same power as most modern day .46's or even a tad less, and it was all the power the plane needed to lift some pretty heavy loads even way back when. A modern day .91 2 stroke IMO is just plain extreme overkill. That plane will float forever when it's lightly loaded, and I think you'd just about have to kill a .91 in the air to land it unless the thing was built heavier than all get out.