Go take A peek at the SK .90 sold through Kangke/ Super Kraft. After I tried my first one I have been sold on them, outstanding engines and 100 bucks all day long. Well, maybe they have gone up sense I last looked. They made A bit of A mistake in there book, it breaks in with A 15X6 prop, anything smaller and they tgend to run lean. www.kangkeusa.com I use these engines now in anything from 60 to 90 size planes.