Tower .75 by far is the best engine for the money out there! They run like a watch, have a ton of power and great transition characteristics. The Tiger 60 I had I flew with an older K&B .65 Sportster and it ran and flew well on that engine but the Tower would be my first choice by far. Second choice would be a Super Tigre .75, these engines are very user friendly, ringed, lots of power, and once broken in nobody ever has a complaint about them. Had one on a Super Sportster which flies very similar to the Tiger and it was a rocket.