YourOilShop - Spark Plugs and Indexing Washers for Harley-Davidson Motorcycles

Ph: (313) 537-5026

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	Spark Plugs and Indexing Washers
	for Harley-Davidson® Motorcycles
	* Spark Plugs are priced individually *

* Consult your owner's manual or service manual for proper part fitment, torque specs, and other important information.

Twin Cam & Sportster * (12mm)
	Harley-Davidson® 6R12 #32362-04	Your Price $3.95 Each	QTY
	Champion #RA8HC	$2.95 Each	QTY
	Autolite #4164	$2.95 Each	QTY
	NGK Regular #DCPR7E	$3.50 Each	QTY
	NGK Colder #DCPR8E	$3.50 Each	QTY

Evolution Big Twin & Shovelhead * (14mm)
	Harley-Davidson® 5R6A #32342-04	$3.95 Each	QTY
	Champion #RN12YC	$2.95 Each	QTY
	Autolite #4265	$2.95 Each	QTY
	NGK #BPR5ES-11	$2.95 Each	QTY

Other Harley-Davidson/Buell Models * (12mm)
	Harley-Davidson® 10R12 #32335-04	$3.95 Each	Sold Out

Spark Plug Indexing Washers
	12mm, Set of 8 = 2 each of 4 sizes fits most Twin Cam and Sportster	$9.00 /set
	14mm, Set of 8 = 2 each of 4 sizes fits most Evo and Shovelhead	$9.00 /set
Want to save the UPS shipping charges? Are you ordering only index washers and don't need a tracking number? Call Amy at (313) 537-5026 with your credit card information and she will put them in an envelope and mail them to you for a total of $10/set.

Spark Plug Indexing
One of the simplest ways to improve the combustion in your engine is to index the spark plugs. Indexing the plugs ensures that the gap is facing the combustion chamber. If the stem of the ground electrode is facing into the chamber, then the spark is shrouded from the majority of the fuel/air mixture (photo #4). When the stem of the ground electrode is facing away from the chamber, the fuel/air mixture will burn more quickly and completely (#2, #3). The easiest way to accomplish this is to mark the insulator or metal base with a felt tip marker showing the location of the ground electrode stem. Install the plugs and torque to 10 ft-lbs. Ideally, the gap will be facing toward the intake valve or centered between the intake and exhaust valves (#2, #3). You want to be able to see your mark on the plug (#1). It's best to have the line fall between the two head bolts. If they are not within this range, try swapping the plugs from the front head to the rear head and vice versa, and they will usually come pretty close. We sell indexing washers in 4 thicknesses for both the 12mm and 14mm plugs, but they are rarely necessary. While some people may notice a difference in their engine’s performance, most will not. As a general rule, we recommend replacing the spark plugs with new standard plugs every 5,000 miles.

Click photos below for a larger view - image will open in a new window.

#1 This is what you see from the outside	#2 This is what it looks like from the inside	#3 Correct indexing	#4 Incorrect indexing