ORIGINAL: bigedmustafa
Nathan King didn't check back after I replied to his post. He's running an O.S. 1.60 FX on his Ice Point. I'm not sure why he suggested you get the YS engine when he didn't choose one himself.
If you read the Venus II thread in the pattern forum, the 1.20 AX is far and away the most popular choice of engine and a great match by all accounts.
I suggested the YS because the OP was looking to get his hands wet in four stroke engines.... And it is the best engine. Not that the 120 is bad, it's a good choice too. I chose the 1.60 because it's brutally simple and very powerful. The only downside is that the pump tends to flood the engine if you don't get it started right away. After the first flight it's a piece of cake. It even hand starts very easily.