Just thought I would share this just in case anyone in the future has the same problem.
After deep cleaning my carbs and rejetting, bench syncing etc etc. I found that I had a problem with the choke not working correctly (even after buying a new choke cable). They butterflies just wouldn't close properly, felt really stiff and sometimes wouldn't close at all.
To overcome this problem, I put the choke on (butterflies closed), then I loosened (1/2-1 turn) off the screws holding the butterflies to their shaft so they all seated correctly in the place they were supposed to be when the choke was on and then tightened them back up again.
This resulted in a really nice choke, which works every time and has a smooth feel.
