Yep. The heat cycle method is great for the older tighter PRS sets (which were very tight). Make sure you heat the cylinder area very well before trying to start, and maybe even loosen the glow plug slightly to ease the compression and get the motor turning over. Once it's running get it off the starter box and running on the ground straight away, just slightly rich with the head foiled to keep a good temperature in the motor. Cool running and idling it on the box for a few tanks is murder on a new motor.
Check out the break in info on the Tech Tips page of our web site at www.go-racing.co.nz

The older Gen 5 and earlier models took a lot more tanks than the new GX motors before the pinch subsided (around 2 gal in some cases).
The new GX motors have the sleeve fit just right. The majority of the hard break in is done within 12 - 15 tanks, yet the motors hold that last little bit of pinch and wicked compression well into their racing lives. Seems GO have got the formula spot on with these new motors.

If you can, pre heat your motor everytime before you start it from cold.
This will increase the life of your motor heaps. It's not always possible, but do it whenever you can.