I might have sorted it.Earlier today I removed seat and removed earth connection to frame closest to the battery.The frame has been painted and underneath the connection which has been made with a flattened piece of copper pipe was quite dirty.I have cleaned thiis and bike has started straight away.This may be a fluke but could this be the problem.By the way thanks to both members for their input it's appreciated.

could it not be flooding the bike with the fuel tap not shutting off? could be why once sat for awhile it doesnt like to start and hard to start coz some of the plugs are wet. like leaving a bike on prime position can easily flood a motor