Originally Posted by grizz1

It certainly sounds like the motor is still way tight. If it's creaking like that when you un-jam it, then it is TIGHT.
Leaning the top end when it that's tight will result in weak performance, and may be the reason for your flame outs.

Put the HSN back to flush and lean it on the LSN - which controls the fuel flow from idle up to 90% throttle on these motors. That way you won't be starving the motor by choking the fuel supply off at the HSN.

Sounds like it just needs more tanks. 15 tanks of heat cycle break in with the head foiled and running slightly rich should be plenty, but looks like you got an extra tight motor.
As a rule of thumb, we normally judge if a motor is ready for race tuning by - run a tank through, then stop the motor. Within 30 sec of stopping the motor, if you can turn the motor over in the buggy using the flywheel from underneath with your finger (just turn it over - it will be hard work), then the motor is ready for a reasonable race tune.
If you can't get it to turn over and can still feel metal pinch resistance, then it needs more tanks before leaning it out.