Noise and vebration on a Flymo 330?

My neighbour and I both have a Flymo 330.
His quiet and gives a nice short cut using 3 spacers.
Mine is set up the same way ,but does not give a short cut,just tears up the lawn if I add another spacer.
It also roars compared to his.
I have stripped it down and noticed tha belt is very tight and when I removed it I noticed that the Hover housing is very stiff.
Is this normal or shopuld I take the spindle ot to have a look.
Any help would be appreciated