lumpy, low power bottom end

My Trophy 900 t reg has started getting lumpy low revs, after 4.500 rpm its ok. Was fine when I got it, but its not been ridden much (due to a bad shoulder) but I had taken it to a garage a while back (around a month-6 weeks ago) due to this problem, and it sorted it for a while, but took it out today and its awful. Problem is I have a biking trip to france on Tuesday, so no time to take it back to garage.

 

Gave it a strip and found a 3mm split in the vacuum hose, so all sorted now, thanks ian for you reply