Hey Scott

If you're saying that it runs smoothly, until you get to 1700RPM or more, there probably isn't a head problem, its probably the engine.

using your setup, use regular gas and either Yamalube2 mixed at 32:1 or AMSOIL at 50:1 (its good to 100:1 but there isn't a lot of leaway for any mistakes at that ratio). Set the low end needle for around 7/8-1 turn and the high end around 1 and 1/4 turns. Filter the fuel at every step, and use a good quality filter on the model, its amazing how much garbage is in gasoline.

take a look at the primer bulb when you set the model down from flying. If its still got fuel in it, all is well. If its empty, hot air is blowing on the carb and causing the regulator to misbehave.