Spark Plug Changing Tips

I did a little research among all of the R3 sites before doing a spark plug change on my bike while doing the Eastern Beaver headlight relay install. Since the cold months are upon us here in the US and the winter maintenance fairy will be calling, here is a combination of what I found and tried to make the process a breeze.

1. You can rotate the gas tank completely out of the way without disconnecting the fuel lines. Simply remove the tank bolt and turn it sideways across the frame where the battery is located. There is plenty slack in the hoses, but make sure you put down a towel to prevent paint damage or contact with the battery terminals.

2. If possible blow out the spark plug hole with compressed air before removing the plug. I keep a clean motorcycle but there still was quite a bit of crap in the wells on my bike.

3. The stock plug socket works fine, just use a 17mm or 5/8th socket on the top to loosen the plugs.

4. When installing the new plugs use just a touch of anti seize on the treads and they will go in smooth and come out 30 or 40 thousand miles later with no problem.

5. Use a piece of 5/16" fuel line about 3 or 4 inches long pushed on the top of the plug to set it in place and hand tighten prior to using the socket. With this, the risk of cross threading is all but eliminated.

6. Do not over tighten the plugs. A good final tug on the socket is all that is needed to seat the new ones.

My bike had the original plugs still in after 30k and what a difference a change made. I know allot of these tips well known to the real wrench spinners on this site, but maybe they can assist someone doing this procedure for the first time.

what is the plug gap?

dirtbagbiker said:

what is the plug gap?

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0.9mm but if you switch to Iridium plugs you do not need to set them and they are supposed to last a lot longer.

I found it easy enough leaving the tank in its raised position.
I think I may have moved the coils from their mountings for a little extra room.

zimtuff said:

0.9mm but if you switch to Iridium plugs you do not need to set them and they are supposed to last a lot longer.

I found it easy enough leaving the tank in its raised position.
I think I may have moved the coils from their mountings for a little extra room.

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One does need to check the gap on iridium plugs. There is a gap spec and the setting could be off if a plug was treated rough in shipping and handling. Always check them all ! And,,, be VERY careful how you make any adjustments. Iridium spark plug center electrodes are delicate.

Here is an excerpt from an article on Denso iridium plugs.

Q. Do I need to set the gap?
A. Generally, no. The DENSO Iridium Power plug comes pre-set with a protective sleeve over the firing end, to protect the gap from accidental alteration. DENSO Iridium Power’s ultra-efficient firing power compensates for normally recommended gap settings that are smaller than the pre-set value. In the cases of vehicle modifications (nitrous, turbo-chargers, super-chargers, high power ignition systems, etc.), some adjustments may be desired. Or, if you prefer to remain consistent with factory specifications, you may adjust. However, please be careful not to place any stress on the fine center electrode during adjustment. You could accidentally break off the very hard, and therefore brittle, tip.

And if you need to adjust them,,,

Q. How do I gap Iridium plugs
A. Before attempting to gap any DENSO Iridium Power spark plug, please review the specification chart to see the factory-preset gap. In most cases your Iridium Power plugs do not need to be gapped. Even with small variations in the factory set gap the ultra-efficient firing power design will compensate for those small variations. Should you decide to re-gap your Iridium Power plug, use extreme caution as improper gapping may damage or destroy the Iridium center electrode or porcelain center. To increase the gap size: Step 1 Use needle nose pliers or spark plug gapping tool to bend the ground strap up to the desired height. DO NOT LET THE PLIERS OR GAPPING TOOL TOUCH THE IRIDIUM CENTER ELECTRODE OR PORCELAIN. Step 2 Re-check the gap with a calibrated gapping tool. To decrease the gap size: Step 1 Use the same method as above, however bend the ground strap down to the desired height. DO NOT LET THE PLIERS OR GAPPING TOOL TOUCH THE IRIDIUM CENTER ELECTRODE OR PORCELAIN. Step 2 Re-check the gap with a calibrated gapping tool. WARNING: Failure to follow these directions may permanently damage the spark plug. Note: Never use a round gapping tool to check the gap or to increase or decrease the gap setting.

muleskinner said:

One does need to check the gap on iridium plugs.

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I didnt say dont check them,I said you dont need to set them. If they are damaged I would be returning them.

zimtuff said:

I didnt say dont check them,I said you dont need to set them. If they are damaged I would be returning them.

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Wow! Are we touchy today? Yes you can and do need to "Set" them. I posted the info from Denso in my prior post. Denso states you need to "Set" them. They also tell you how to properly "Set" them. If I found a plug with the gap closed i would regap it, not take it back to the store. Now if the plug is "Damaged," then yes, I would return it to the store you purchased them from.