Spark Plugs - How long do they last?

[michaelphillips]

ive started a topic in the garage, regarding spark plug, and will update when weather gets better, going to pull out dr pulleys to clean housing and checking belt etc soon so take some pics of plug and the belt, to see how that is doing as it was an aftermarket one £22 only, yet gonna see how its doing as a check, if not happy with it i will bang on the original belt i have ordered from italy, which was only £32 delivered!!! and keep the other as a spare, for when i go away. cheers