Was the reason it was put away for all that time because of its ignition “problem” ?.If so then a new coil is required.Before you buy one though just remove the thin cut out / ground wire on the coil terminal and try again.If still no spark (and you are sure that the spark plug,HT cap and HT cable are all ok) then a new or replacement coil is the answer.
Thank you for your reply – if I need a coil, where would I get one? the ones I have seen on ebay look nothing like what is fitted, the one on my engine is an aluminium thing.