Polaris 2003 Pro X Service Manual page 37

HEAD CC REMOVAL EXAMPLE
Total number of CCs to remove from the head = Old IHV -- Desired IHV
Removed CCs = IHV -- IHV2
Removed CCs = 1.299 cc
I =
Displacement
I = 0.01186
To find out how much to cut off, multiply the number of CCs you need to remove
by the number of inches to remove per CC:
Thickness to remove = I
Thickness to remove = 0.015 in
PORT OPENING DURATION
Port open = 81.5
Duration closed = 2
Duration closed = 163
Total duration = 360
Duration open = Total duration -- Duration closed
Duration open = 197
Duration open
Percent open =
Total duration
Percent open = 54.722
Stroke
cm.
2.54
in
in
cc
Removed CCs
This indicates the degrees after TDC that the exhaust port
opens (and also the degrees before TDC that the port
closes).
Port open
100
Number of inches to remove from the
cylinder head to equal 1 cc
ENGINE
2.5