I recently bought a 78 gs 1000. The bike will idle just fine but when I take it out on the road and ride around a bit it will rev up anywhere between 4 and 5 grand. It happens off and on whenever I pull the clutch in. I'm one hundred percent sure it has nothing to do with the carbs they are squeaky clean. Its not the throttle cable enough slack and its not catching. Any other ideas would be very helpful.