Harley- Davidson Top Dead Center (TDC ) and Advance Timing Marks for Various Models

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Ankeny, Iowa 50021
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CDR, CDS, SRē & EPē

When timing is at Front Cylinder (TDC)
on Big Twin the Pins on the Rotor will be Positioned as in above picture.
 		 To 1980
CDR, CDS, SRē & EPē

When timing is at Front Cylinder (TDC)
on Sportster the Pins on the Rotor will be Positioned as in above picture.
 

           Front TDC      Front Advance 35°
1980 to 1996

           Front TDC      Front Advance 35°
1996 - Up

           Front TDC      Front Advance 20°
S&S Engines All

           Front TDC      Front Advance 35°

If your not sure as to which mark is the TDC, as you roll the engine over in normal operating direction, the first mark to go through the window is the Advance Mark.

If rotor pins are not in the positions above or you can not rotate module to reach timing pins, check that rotor notch is seated correctly or be suspicious of cam gear being pressed on incorrectly in the case of a Big Twin.