Heres a strange one - bike has just failed its MOT (i am in england) - apparently when the handlebars are turned to the right the revs rise, then reduce back down as the bars are straightened! sounds like a cable routing/jamming issue? Just a quick question before i start removing tank/carbs/cables - anyone had anything similiar.
On an aside - www.bitzforbikes.co.uk in the UK for spares - brilliant service, great prices. Ordered a new rear disk 12 noon on Monday, arrived Tuesday morning! Can highly recommend them.
Sounds like your throttle cable is just routed poorly. Make sure it crosses over the head tube before going into the engine compartment.
Check the choke cable too, had exactly that same problem when I put the GenMar risers on. Had to reroute the cable behind the fork leg. Pulling on the choke cable on a warm engine opens the enricher jets and speeds up the engine.
I think it might also be an adjustment issue; make sure you adjust the throttle freeplay at the tighest point in the steering arc. In other words, set the freeplay at the right throttle lock and see if that helps.
(although I agree that you should check the routing to make sure the cable isn't binding anywhere).
thanks guys - looks like my Sunday is sorted out for me...