[otcpharm]

You can dip them in kerosene but no brushing. You'll snap that pencil thin electrode right off if you try.

Pshaw! I take them out every 100 miles, dip them in denatured alcohol (man that's a good solvent) and brush them with a brass brush.

Clean up like new every time with nary a break or misfire.

 

[otcpharm]

I just replace them not worth the risk of having it snap off inside the engine, IMO. 8)

Keeping an eye on them by mic'ing them each time they're out and comparing against the baseline of a new electrode. When they wear, they're gone -- got a spare set standing by.

 

[otcpharm]

Not supposed to even touch the ends. The iridium is a coating and will come off if you brush them.

Um...no. It's an alloy tip that's attached to the electrode.

 

[otcpharm]

page 101 owners manual..This motorcycle uses spark plugs that have an iridium coated center electrode.
Be sure to observe the following when servicing the spark plugs.

Do not clean the plugs. If an electrode is contaminated with accumulated objects or dirt, replace with a new one.

Well you can read the rest. page 101 of your owners manual. It's a coating or maybe a misprint. My bike came with NGK.
Denso says it's iridium and doesn't mention a coating but they also do not recomend touching the electrode or porcelain.

OK, pretend you're the manufacturer.

You think to yourself, "hmm, automobile spark plugs in the old days were good for 30K miles. Now they're good for up to 100K. That just won't do for motorcyles - after all, we need to make a profit and there aren't enough sold (unlike cars) to sufficiently pad the old wallet."

What to do? AHA!! "We'll just tell them that they have to replace them every 8K miles, and if they so much as BREATHE on the electrode, the miraculously micro-thin coating of iridium will come of and the plug will cause the bike to melt down or explode into a million pieces while they're riding it, possibly killing them."

Horse-feathers.

Remember that automobile manufacturers said for years that you HAD to change your oil every 3K miles, OR ELSE (and now they're saying 7500+ is OK, while in Europe they're doing 20K+ on a change with 100K+ mile vehicles). And that was in the owner's manual too...