ive just had a similar problem on me 1100 sport ,turned out to be poor connections in block at rear of bike .Also a poor earth on rear unit .Like they all say its just a question of checking all connections ,at one point it was driving me mad ,all the best
So when yer gonna bring it dahn 'ere so I can take a look see and ave a drool ovver it then Johnno, OH yeah yes owe me a test ride too
soon as weather warms up .