Its easy to check. If its the powervalve its more likely to be an intermittant issue. Jetting should pretty much run poorly any time you run in certain conditions.
To check the action of the powervalve remove the pipe, the RHS pv cover, put pipe back on and run the bike on the stand. You will be able to see the powervalve move with the revs. You can also disconnect the actuator arm and check that the plate rotates freely. Check the freeplay while you're in there. Whatever you do though, don't roll it around with the arm attached, or pull up on the arm. You can dislodge a ball in the governor.
