Anyone with experience in doing this. I did it recently with my bike and it seems to have made a difference in its running a bit better. Or, is it just my imagination?

 

What do you mean by "indexing"?

Setting the gap?

 

It is likely you imagination. Racer index plugs to shave a tenth off of a quarter of a mile run. I doubt if the average guy is gonna be able to tell a difference.

 

Indexing plugs won't even shave a tenth of a 1/4 mile time, not even a hundreth. Unless you're a Pro Stock racer, it's not worth the time or effort.

 

This is why there are side electrode sparkplugs..no need to index, the spark is "exposed" to the combustion chamber.. Airplane reciprocating engines have had them forever...the combustion chambers are two large to have a conventional type plug. I have read that in automobiles it is for mainly improving fuel efficiency.

 

Indexing was originally done to gain clearance between the electrode and the piston dome. It has since been proven to promote flame travel. Not worth it on a street engine of any type, too many other places to gain more power first.

 

In theory indexing the spark plugs will make any engine run better, but the change is so small that it is unlikely that you are feeling it. If you have the time, then you can only do good by indexing spark plugs, but the gains tend to be very small if at all.

 

On my carbed Evo, had been running once in a while at the local drags and screwing with plugs I noticed when I indexed the plugs so that the electrode was aligned with a clear path to the intake, the plugs ran a lot cleaner. I do it now just for that reason and it does work. Its probably better on the daily rides than on the track 'cause of the varying speeds and loads. Or maybe I'm just a little ****. Don't see any performance increase though.

 

Well.......I kinda thought that it was my imagination playing tricks on me.I guess so. You know what they say, things run better after they are waxed and polished, etc.

 

You need to pull the heads to index plugs properly.The open part of the plug should be centered on the intake valve stem.I doubt it will make a difference on any street engine.I used to run analcohol engine and it didn't seem to help that engine.It wasn't a bike though.