RE: Brodak 25 engine
The Brodak 40 is a very good STUNT engine. It fits the same mounts as an OS 40 or LA40-46. Has a bit more power than a Fox Stunt 35 and has an excellent 4 cycle run. In fact, it takes some doing to get it to run well flat out in a 2 cycle.
The Brodak 25 is more of a sport engine. It is the lightest 25 available and, depending on the venturi size, has comparable power to any of the other 25's. It likes to rev and it doesn't do as well in a 4-2 stunt run.
The Brodak 15 is a good sport engine. Similar to the LA 15. It is not a powerhouse, but handles 3 ft. or so plane nicely.
They all have a bit of a muffler problem in that the mounting bolts screw into the engine. In a crash they are more prone to breaking the rear part of the exhaust port.