Over the past several years, I've tried OS, Evolution, and Super Tigre. By far the OS's were superior than both. I currently have two OS 46's, one OS 50, three OS 1.20 AX's and one brand new OS 75 AX. The .75 is new and still in the box except for test fitting it on the Protege, it has not run yet. I also had an OS 52 Surpass four stroke that was a great engine. Someone wanted it more than I did and offered me a price that I just couldn't refuse, so I no longer have that engine.

But I can tell you that I had three Evolutions, a 46, a 60, and a 100. All three, well, I can't say they ran well, because I had considerable difficulty getting to run, let alone run long enough to burn a full tank of fuel. I won't go into that because I've already discussed it here on RCU.

The Super Tigre is a replacement for an OS 61 SF that needed new bearings. I bought it used and flew it on my Tiger 60 for about six months, then removed it to replace the bearing. I put a Super Tiger 75 on board just in the interim. I have no problem with how it ran, but again, I've outlined the problems I had with it here on RCU.

Now for the OS's, well, I've lots of flying hours on each and every one of these fine engines and have yet found anything to even mention let alone complain about. I did have one that would dead stick frequently until I fixed the fuel tank, and that was not a fault of the engine, that's for sure.

So, my vote is for OS. I am willing to pay the extra to get the quality. Period. I've seen and flown with the cheapies and they just won't cut it for me.