If you're using the same battery forget it,good chance that is the problem,they don't have the same power output as car batteries so you might get lights etc.DON'T start looking for faults like cdi or immobiliser you didn't have a fault with those parts before you laid it up!!!Get a new battery (£15 ?) and charge it up as per the instructions, if it doesn't fix it then start looking for other causes.Also check/replace the batteries in your remote,batteries die over time cdi and immobilisers don't just because you haven't used them for a while.Good luck.
Old biker git.
September 2014