Pump?? I thought they were gravity fed

These badboys need a proper spark to get them going, especially if its been laid up! New plugs will see her running and a new battery wont hurt! Check the plugs for fuel when you remove them, and just do a quick check for spark on the new ones.

Those backfires are impressively loud!

They most certainly are, though I admit I am surprised that you heard them all the way over in Bristol when I'm in Reading

I've ordered a plug tool from Wemoto so I can check it out. Thanks for the advice :)

If it's trying to fire but you are getting a backfire make sure your plug leads are on the correct way round.

yeah checked that.. they're ok :) Has anyone tried CR8EHIX-9 iridium plugs? I can get them on ebay for pretty much the same as the standard CR8EH-9 plugs.