by Sparks_333 » Wed Jan 02, 2013 11:27 am
Turning the throttle with the bike turned off will only open the butterfly valves that allow more air into the carb. Since carburetors rely on vacuum pressure to lift the diaphragm and hence needles to let more fuel be drawn through the jets, you won't see any action here unless the engine is running.
I'm no expert my any means in the mystical black art of carburetor tuning, but I have messed around with them on a few ninjas and gpx 250s. If you want to play with the carbs, be prepared to pull it apart and put it back together a few times to get it right!
Have the carbs been adjusted at all or are they stock? If it's flattening out down low the carbs might be gummed up and need a clean. If you've got them apart then (carefully) dismantle the diaphragm, needles, lower assembly and main jets and give them a thorough clean. Make sure you can see through the main jets and there should be no gunk inside.
What was the throttle position when it flattened out?
2009 Kawasaki Ninja 650R Green
2010 Kawasaki Ninja 250R Black/Green (Track Bike)
1998 Kawasaki Ninja ZX6R Green - "Fluffy" (Track Bike)
"Never ride faster than your guardian angel can fly."