RE: CMP Pro Marathon 20~24cc AEROBATIC AIRPLANE
A DLE 30 will be an incredible match for this plane.
You will not have any weight issues with this engine. It is lighter than the engine I used!
If you look in the fuselage shots, you'll see that on either side ( front and back ) of the gear mounts I epoxied in wide triangular stock to add forward-backward gear mount strength.
There is some tri-stock already there as it comes, but I believe in trying to spread out the load forces as much as possible.
In prepping the plane I also made a 30 min epoxy mix adding about 10-15% by content of alchohol to thin it out.
I spread this LIBERALLY over all of the internal wood structures to help strengthen and seal the wood joining areas.