hey mick - I prefer frugal! like I said on other entry in repsonse to other entry from other person on site I tried iridium & did not notice much difference & recently when went to hotter plug changed (back) to non Iridium.
OK, I'm shamed into it - will buy an new plug, though like Mick as an old hand @ riding British bikes in 60s/70s used to just wire brush or otherwise recycel them & keep using same one for ages!
darn, even though I'm used to it by now I hate pulling the tank - never had to on my 81 Yamaha SR500 single.
thanks for input everyone!