Sorry Chuck, would have to disagree with you on that one.
Spark goes in at usually 20 or 22 before TDC ( retard points on the LH mag are usually about 10 degrees less ).
The increase of RPM to 1700 increases the burn temperature, even when fully rich, therefore will generally burn off carbon/oil.
The 540 or 520 does not have vacumm advance system or similar ( that i am aware of ).
The volumetric efficiency does not vary all that much ( excluding ring and valve leak ) with RPM.