Timing marks

[QTreiber]

Hello,

I was checking the ignition timing on my 1979 Special II with a timing light.

At 1,200 rpm one cylinder fired a little to the left of the "F", the other one a little to the right.

I checked the shop manual but it is still unclear to me where exactly they should fire (between the marks to the left and right of the "F"?).

Any help would be appreciated!

Armin

 

[5twins]

Yes, anywhere between the short slash marks to the left and right of the long "F" slash mark is acceptable. There is about a 4° or 5° "range" that is considered OK. Be aware that where you set the idle timing is going to determine where the full advance timing is too. This is because your advance unit is made to advance a certain set number of degrees, something like 25 I think. So, be sure to check your full advance timing as well. If it's too advanced, retard the idle timing a bit.

You should be able to get your full advance timing on it's mark (or just a hair under) while still getting the idle timing somewhere in it's "range". If you can't do that, it usually indicates your advance unit is worn. As the advance unit wears, the amount it advances grows.

 

[QTreiber]

Thank you, 5twins, very helpful!

Armin