Guys, I just started flying a UCD60. So far I like it. I'm a beginner/intermediate flyer. Can do some basic manuvers and burn lots of holes in the sky. No 3D yet. I'm using a ST90 w/ an APC 13x6 prop. While the ST90 seems to be able to hold it vertical, there is no more umph to get it going after it's stationary. You guys are running larger engines. Would you think the ST90 is marginal like it seems to be? Do I need to be thinking about a different prop?

Thanks for any feedback.