Plug change - 11,000 miles.

Ok, so my bike has done 11K miles, has had regular oil/filter changes and has had the air filter cleaned regularly.
Bike runs really sweet and yet is still on original plugs (04 plate)
I am best leaving well alone or replace plugs anyway ?
Don't want to pay a dealer so will do myself if required, easy job aint it ??

Not too technical but just damned fiddly changing the front one. On the sk1 I had to remove the horn and its bracket, unscrew the bottom of the radiator (not sure but you might have a radiator guard to remove as well if you've got a k4), rotate the rad as far forward as it will go and wedge a block of wood into the bottom of the gap. Then you should have just enough room to unplug the wire and get the plug socket from the bike toolkit down the hole and onto the spark-plug. The rear one is alot easier to get to. I seem to remember that you just have to lift the fuel tank up.

Like you I didn't think mine needed changing but it was like riding a new bike afterwards and the old ones didn't look particularly bad.

After getting all the stuff out of the way, it is a very easy job. As simple as undoing a fiaring bolt and screwing another one in.

To be certain they'll come out again in 11,000 miles, pop a teeny bit of cooper slip anti seize on the new threads before you put them in