| Most "NGK"s are copies, not original items from the NGK factory. They can have the wrong heat rating and leak out pressure. This pic shows the fake one I bought that had "painted" metal that flaked off a little on the ground electrode. After riding with it 2 miles it showed no deposits on any of it, probably because it got too hot to allow them, that and the fact that the painted metal prevented deposits. The true one (iridium) on the left shows normal deposits.   NGK's website gave this list of authorized dealers:  |