Which of these two engines has the most power and weight/wing area carrying ability?  The LA 25 is listed @.61 HP but the Brodak 25 is unrated.

I intend to use one or the other in an Umland Coyote, which was originally designed for 35 and up.

   I have only run the 25LA. The current versions are plenty for a Coyote. My first experiments with the 25FP were with Ted Fancher's Coyote, and this is where we found the "homing" problem for the 25. It was perfectly acceptable, it just didn't want to stabilize at the right RPM,  so it was always just a little fast. Put the 20FP on there, worked perfectly just like the Skyray.

    I would expect either engine would be more than sufficient if you let them rev up enough. With a very pointy airfoil as on the original, you need all the help you can get to avoid stalls.

    Brett

Remember the design dates to the days of the Fox and OS 35 and McCoy 40 era. Modern 25's are more then their equal. but there are a lot of those old engines around and they still get used so the origional engine recommendations are still valid. Just keep it light and you will be satisfied with it.

   If that's the question, yes, certainly, I would expect either engine to provide much better performance than something like a Fox 35, McCoy 35, etc. could have back when it was designed.

    It should be kept reasonably light but that's not because of the engine.

     Brett