Spark plugs

[PaulSmith]

I used to swear by iridium plugs but I eventually realised that it was just the "new plug effect". Any new plugs are better then old plugs, Iridium or otherwise. Yes they last longer, but unless you plan to ride around the world non-stop with no access to servicing, why would that matter? I usually change my oil at about 4,000 miles. I change my filters every second oil change and my plugs every third oil change (so about 12,000 miles) even when they don't need it.