I used an OS 65LA in my first trainer, a Superstar 60. I'd like to recommend this engine as I'm sure lots of people use it with great success. Unfortunately, I can't. I had lots of problems with it. This engine I think was the main reason it took me so long to solo, too much fiddling to get it going. When I finally got it running right (about a year later) I put the plane through a tree....

I eventually soloed with an LT-40 which I've used with both an Irvine 39 and an OS 46FX.

Based on my experience with the 46FX, I'd also like to recommend the 61FX, but the MAN article a couple of months ago stated that it's weak powerwise, with less power than the 65LA.

There's a plethora of cheap Chinese engines to choose from, many people swear by them and some swear at 'em. I wouldn't go there due to quality control issues...

If I were to get a 4*60 or Tiger 60, I'd power it with an Irvine 72, based on my experience with the 39. At Quantum Models they have them at $137.99 for the 61 & $152.99 for the 72...