Originally Posted by cdelong
I use Cyrul's WOT method. I mill a spare head down so it has only two or three fins remaining to keep temps up.
Up north in the winter you may need a heatgun, but down south or in the summer the milled head is enough to keep temps up to 180- 200F at WOT.
It's a good idea to mill an extra head but the problem is getting that extra head. Most people don't have an extra head for a new engine especially one as new as the Ninja.