View Full Version : Timing light question-

08-25-2012, 05:30 PM
I have a timing light (30 year old Sears) with the "dial-back" feature but I am beginning to believe that it isn't accurate.
I just set the timing on my Datsun. I set it to the "5 BTDC" on the pulley (with the gun set at "zero") but when I dialed the gun so that the flash was on "pulley zero" the gun read "8 BTDC".
Has anyone else ever "calibrated" their gun this way?
Similar results?