Motorcycle Repair: 1980 kz 440, needle valve, air cleaner

Question
I have achopper project and i have the bike running but the motor runs eraticly. Most of the time it idles nice but when you goose it the RPM's stay high and then slowly come down.Can you tell me what and how the motor would react with a bad diaphram. Thanks.

Answer
First i would try checking the cables to see if they are not in a bing causing them not to retact .because when you goose it you are manually giving it the gas . when you let go the cable should return to its same posotion, if not you may have a bad cable or bad butterfly in thre carbs ,or even a dirty housing that the slider goes up and down iside  the carb . remove the air cleaner so you can watch the the needle valve inside the carb to see if its going back down as fast as you release the throttle.I hope this helps you . please feel free to contact me if you need more info o.k.

                P.S pleasae dont forget to leave feedback thanks,

                                  Mitch