I have never bothered indexing my spark plugs in the past, but I recently thought I'd do it. Just so I could say I've done it. I bought a set of Morroso indexing washers and gave it a go. I started off by mixing and matching spark plugs in different holes and found I didn't need ANY of the washers; every plug coming out facing the right direction (or close to it).

Have any of you indexed your spark plugs?

I index my plugs on my HD Sportster that is set up for drag racing. On a 100HP v-twin it can give an extra 2-4 HP.

I have never bothered indexing my spark plugs in the past, but I recently thought I'd do it. Just so I could say I've done it. I bought a set of Morroso indexing washers and gave it a go. I started off by mixing and matching spark plugs in different holes and found I didn't need ANY of the washers; every plug coming out facing the right direction (or close to it).

Have any of you indexed your spark plugs?
my AR3932 plugs have a cut back electrode , so no matter where it points ,it still fires center

my AR3932 plugs have a cut back electrode , so no matter where it points ,it still fires center


I don't quite follow you. Are you saying the side electrode has been cut back and then bent down so it fires sideways to the ground electrode?

I don't quite follow you. Are you saying the side electrode has been cut back and then bent down so it fires sideways to the ground electrode?
no ,it is cut back to just about even with the edge of electrode. it seems to fire up i ve never seen this before either, but Patriot Performance, where i ordered motor, recomends these plugs they are also much shorter in length, which clears headers better on angle plug heads

no ,it is cut back to just about even with the edge of electrode. it seems to fire up i ve never seen this before either, but Patriot Performance, where i ordered motor, recomends these plugs they are also much shorter in length, which clears headers better on angle plug heads


I think I understand now. It doesn't OVERHANG the center electrode. Am I getting the picture?

exactly, i dont expect that they will last 100,000 miles but they do throw a big flame