I just got my bike this weekend and although it´s a ´80´ model and not a ´81´ it should be about the same. I was having the same problem, but instead of just cleaning the jets I took the carbs off and put them in a mild carb cleaner for 24 hours,after disassembaling them. It is a very precise job to put them back together once they are apart.I´m not trying to insult your intelligance, not knowing you, so I´m sorry if you took it that way. But if you dont feel comfortable with it, call your local dealer or repair shop, for advice, or prices on doing the job.