Unless you see evidence of gunk and junk in the cooling system, flushing is over rated. Especially 3 times. Holy ****.
The Fjr has a bypass in the cooling system so pulling the T-stat or waiting for it to open is not necessary.
Just drain the old stuff. Fill with water and run it for a few minutes, then drain it again. Fill it with whatever coolant you like, burp it and be done.
Agreed Mike .. thats why I suggest RMI 25 .. after using for a few hundred miles all you do is drain the system and clean out the over flow tank ..then refill