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Kawboy,

Great addition to the post !

Could I ask you if you have ever been advised on the procedure for cleaning Iridium Plugs when required ?
I was told by an NGK Reseller that they should not be cleaned with a wire brush or spark plug cleaner like regular plugs are, due to having a coating on the elctrode tip which would be damaged with anything abrasive............sounds logical.
He also stated the gap should not be altered from its factory setting.

Interested to hear if you have any additional experience with this ?

Pete F
UK

All I can say is that Denso advises on not adjusting the gap. Why, I have no idea. Maybe they are worried that the micro weld between the fine wire tip and the ground bar might get damaged and the tip fall off????.
As for cleaning- I've had good luck with cleaning with Xylene based aerosols like "throttle body cleaner" to remove oil/soot without damaging the ceramic and it leaves no tractable residue. Just my 2 cents which ain't worth much these days.

I was scolded by a mechanic as kid when he saw me using a wire wheel to clean my plugs. He said it's the sure way to render them useless as the wire wheel will transfer and imbed metallic material onto the insulator and cause shorting/misfire. Never did that any more so never proved his point for myself, but it seems logical..

Pretty sure they recommend not gaping iridium plugs because the centre electrode coating is so thin, even inserting the gap measuring tool can take the coating off.

Interesting approach since the gap specification is based on the ignition system/engine application and not something that is typically plug dependent. I've got iridium plugs in a couple bikes and I honestly can't tell any difference between them and any other regular plug I've used.

Just bought a set of these Denso plugs.
Can anyone tell me if the top bit unscrews? Sorry no idea what to call it!
My plug caps need the plugs to have just the small thread to press on.
If these don't unscrew then I guess I'll have to buy new caps.

Yes thay should do