There are a number of threads dealing with the DA50 that you will find interesting.
Check them out.
http://www.rcuniverse.com/forum/Does...1713333/tm.htm
http://www.rcuniverse.com/forum/DA_5...1958934/tm.htm
http://www.rcuniverse.com/forum/DA%2...1903161/tm.htm
Rick P
- motor needs air moving over it to cool it.
I find it hard to believe that the prop can not provide sufficient cooling.... at a continual idle maybe it is not enough but balance of RPM range ????? I don't have the experience just observation of its airflow.