Indexing Spark Plugs
In go kart racing every little bit counts. Indexing the spark plug
is just another little trick to add to your arsenal of hop ups.
Draw a line on the white porcelain portion of your spark plug, indicating which direction the open end of the electrode is facing.
Install your spark plug and be careful not to over tighten. Check your line on the plug to determine which direction the open end of the electrode is facing.
You want the open end of the electrode to face the
exhaust valve. If the head is off of your engine like
in the picture, it's easy to tell where the exhaust valve is
(valve on the right). If your head is bolted onto your
engine, the exhaust valve is located toward the bottom left
(at about the 7 o'clock position).
If the electrode is not pointing toward the exhaust
valve after it has been tightened, remove the plug and install
an indexing washer. Install the plug with the indexing
washer and repeat this process until the electrode is pointing
in the desired direction.
ADJUST PLUG GAP
There are all sorts of inexpensive plug gap tools.
Set the gap by bending the electrode open or closed to reach
the desired gap. We set our plug at 0.045".