Hi blokes, thanks for the Replies, the bike runs fine at cruising speed, it just seems to stutter when doing 30 mph at around 2500 rpm, and not all the time then, I fitted new spark plugs and noticed the rear was sooty but front was OK, trying to find out if it's either ignition or fuelling, someone out there must have had something similar, need to know if they found the problem or not or improved it or is it just the bike, nothing stands out to me at present.
Regards
Paul