Spark Plug Indexing

[volcano buster]

Does anyone bother indexing plugs anymore? I have the head off my engine and this looked like a good time to do it if it provides any benefits. On some smaller 4-stroke motors I used to put together I would do that and it seemed to help.

 

[cascadesnowjunky]

It don't make any difference on a two stroke

 

[m8magicandmystery]

does on direct injection 2 stroke

 

[Laundryboy]

Years ago I used to be that hardcore. I could never tell any difference.

 

[m8magicandmystery]

indexing became less important as the quality and intensity of the plugs improved

 

[mike_s]

It can be used to provide some miniscule amount of safety margin against detonation if you index the ground strap to shroud the electrode from the exhaust port. In theory.

In practice, any net effect will be slightly less than negligeable.