RE: Kangke Monocoupe 60-90
If you are looking at buying another engine and would consider going to Gas, The DLE 20 is an excellent match for this plane.
A "90 size" glow 4 stroke is about the minimum you want for "Scale" flight. I have built a number of them (I used to be the Kangke importer here and was therefore also the SK importer). As a guideline, The SK 90 works fine, the SK 1.30 works even better They are reasonably high torque low revving glow engines. Probably the best Glow combination I used was a Saito 1.00
Program in some aileron differential and you wil find it also turns much better.