I need some good ideas for an engine for a Goldberg 68" W.S. Extra 300. I would like excellant vertical performance, without too much added weight. I tend to lean towards 2-strokes. Ideas?

I had one when then first came out with a ST.90. Verticle was just OK. If your stuck on a two stroke go OS 1.08 or Webra 1.20. or maybe the new ST2300. I'm sure you will get some go four stroke replys. I would also push you that way if you had not mentioned your leaning to a 2-C.
Think about it though. A Saito 1.80 would be sweet on that bird.

David

Several years ago I bought a used CG Extra that was being flown with a ST 90. Overall performance was good, but vertical was marginal. Replacing the ST 90 with a Thunder Tiger 1.20 made a big improvement in the vertical performance. The TT 120 gave it enough reserve power to pull out vertically from a hover.

I also have an OS 108 in a CG Ultimate. The TT 120 and the OS 108 weigh almost exactly the same, but the TT 120 has more power.

IMHO, if you want a two stroke for your Extra, the TT Pro 120 would be hard to beat.