I have a 00 Zx9r. recently had my carbs cleaned and jet kit installed. Ever since then, sometimes when i turn the bike on the tach doesn't register the idle rpms but if you twist the throttle, it reads the rpms normal. Then when you let off the throttle the tach falls back to 0 rpm on idle. If I turn the key off and then back on again and restart the bike, the tachometer reads the idle rpm just fine like nothing happens. So everytime i go to ride my bike i have to start it twice in order to see the idle rpm. Any idea what could be causing this?