Is your prop a 20/8? The Moki 2.10 likes to be broken in using a 20/8 prop. A 20/10 needs to be saved for later on after the motor is well broken in.
Also are you using a tach?
I run a bunch of short break-in-runs using small tanks of fuel on the ground, full out at 6000 rpm. This is a very rich setting. After this I lean it out to see if I can get up into the mid 8000 range. I hold this only for about 1 to 2 minutes and then back off to 6000 rpm again.
My test flights are at about 7500 rpm, a full 1000 rpm below peak power. This is a slow process, I am not looking for the last ounce of power until after several gallons have been used.

Over heating on the ground sounds lean to me.

There are a lot of scale builders out there, Jeff Folley mr Top Gun, that fly a Moki 210 fully cowled on 25+++ pound war birds, down in Florida heat and they do fine.

Also are you using 0% nitro? Moki runs just fine on 0%. If you are using 15% you may be cooking your motor.

On my motors I use 0% nitro, 15% oil. I run a 18/8 on the 180 and a 20/8 on the 210. Bambula props. Good props by the way.

Hope this helps

tonyc