A few months back I wrote a feature in my column on the death of the .61 size engine. I believe the .61 is going like the .40. 20-30 years ago, everyone flew a .40 in their mid-sized planes. In the late 1970s, the OS .40FSR was THE engine to have. We all had them. After a few years they came out with the OS .45FSR. It took a while, but that extra power for a few bucks more caught on. Soon everyone was making a .45, then the newer generation engines started being called .46s.

I remember guys claiming they were always going to fly .40s, but that didn't last. Look, you can still buy an OS .40FX and a Thunder Tiger .40 Pro. Nobody buys them except for an unsuspecting few, I guess, but there are a few around for sale.

When they came out with the .75s and then the .91s in the same crankcase as the .61, the .61 was doomed in the long run. I just checked the price of the Tower .61 & .75. $5 difference. The GMS is probably close to the same. I don't know if Magnum even makes their .61 any more. I do know that when Magnum went to their new XLS series from the older XL engines, the first ones they made were the .46XLS and the .91XLS. With the .75 & .91 you can run a bigger prop if you want to or you can turn the same prop you run on a .61 at a higher rpm. So why, for the life of me, would anyone buy a .61???

Now I know there are guys out there who are going to say you can't beat OS reliability and they will fly their OS .61FX until someone tears it from their cold, dead hand. I'm sorry, I really am, but you remind me of my buddy with his .40. A Tower .75, or any of the other .75-.91 engines, will beat that .61 every time.