And to add to Denny's always good information, make sure that the thermostat is in correctly with the "pill" facing the engine. Sounds like it's a no-brainer but after many years of mechanical work, nothing surprises me. Also, 212 or thereabouts is not too high a temp with a 16 pound cap. With the rise in pressure, there is a corresponding rise in boiling temperature. A 15 pound cap will raise it by 45 degrees.

Denny, I like your 'new' AVATAR