I'm looking for an inexpensive engine for an OMP Yak 65" profile. I'm looking at the ASP engines and found 1 place that caries them. I'm looking at the ASP .91 but I'm a little confused. I don't know what the difference is between these 3 engines. Anybody know what the difference is? Here's the links to the engines. The descriptions sure don't tell much.
http://www.hobbypartz.com/72p-s91aii.html
http://www.hobbypartz.com/72p-s91a.html
http://www.hobbypartz.com/fm01-10-s9...troengine.html

Thanks