I've been training with this nice little plane, but yesterday I noticed a vibration. Motor shaft seems straight, but when I rotate the propeller manually there is a click in a specific point of the circle - sounds like a loose magnet clicking. The motor is still working, but I don't think for long...

What motor should I replace it with when it dies? I can't find any specs on Dynam site...

I think that's the one, but it's expensive there. And it's different from the photo on Dynam site, although it's listed as spare part for it.

This one seems similar if not exactly the same, but I'm not sure about mount, size etc... How can I find out which one is compatible???

On the motors you have shown do they say what prop size they use?if they match your prop or close you should be good,if you can match up the specs on the motor you have then the ones you have picked,then you should also be ok.

As i don't have this plane i can't really say what motor to use but i'd go with the HK one,only because i get most of my rc parts from them,try asking HK customer service to see if they might be able to help.

It's not going to be hard to swap out the motor so just pick one and see how it works out,it looks to me as though you have done most of the hard work by finding the motor that will work on your pane,so i'd say go for one or the other and i bet you will be good to go.

Good luck and let us know how you get on.

I've peeked through the cover holes and the motor actually looks exactly like HobbyKing motor, with the radiator and unusual hole shapes, so I think that's the one. Funny thing that it looks nothing like the one pictured on Dynam site.