Although the bike started and ticks over and ran fine, but, after about an hour it started to play up, I could not get above
45-50 mph it would back fire and cut out if I tried, I changed the plug but this didn't improve things.( so, a very tedious, 100 + mile trip home )

any advice would be appreciated.
cheers Eric.
p/s getting the carbs off looks like a big job.