Ignition Timing

(Difference between revisions)

Revision as of 02:29, 25 November 2006

Engine ignition timing (distributor timing) is the foundation of any tune-up. It is generally the first step you need to perform as all other tune-up and carburetor adjustments depend on ignition timing being correct.

Procedure

1. Check the gap on the plugs then put them back in. Spec is 0.028-0.032 for the A12. I recommend 0.035 for the smoothest idle.
2. Set the point-gap or dwell. Use a dwell meter if at all possible as it is much more accurate than the points gap, Set dwell 49 to 55 degrees. If the points are brand new, a feeler gauge can be used to set the gap to 0.018-0.021 in. Incorrect Dwell can cause rough running, as does bad points. For example, it might only run at high idle, and not very smooth at that.
3. Double-check the timing. Spec is 5 degrees for the US A12 and should be safe for any A12 engine. This must be done after setting the dwell -- because changing the dwell affects the timing, but not vice-versa.
   

Ignition Timing Specifications