Funny you should mention that. My throttle was getting stiffer until eventually the cable snapped. Looks like it had been fraying for a while. They're cheap, so if I were you, I'd just replace it if it isn't the pivot point on the lever, otherwise you might enjoy a lovely 2 mile ride on tickover at walking pace whilst all the cars you'd overtaken over the previous 5 miles tootle past you! It was raining when it happened to me. Of course......