Can anyone help me diagnose this? (Video)
- Thread starter MILLENNIUM FALCON
- Start date
That was a concern of mine, but when sprayed with the propane torch and carb cleaner there is no change in engine speed (at an Idle).
crazypj
Split personality, I fake being smart
Pull the carbs off and connect the throttle cable.
Look at the engine side of carb and make sure butterflies are closing all the way
The slide position doesn't matter a damn, the butterflies control the air and vacuum controls slide position.
When you get it idling properly, try this for shits' n' giggles.
Remove carb top, remove slide.
nothing happens, it still idles fine if everything is set up right
Look at the engine side of carb and make sure butterflies are closing all the way
The slide position doesn't matter a damn, the butterflies control the air and vacuum controls slide position.
When you get it idling properly, try this for shits' n' giggles.
Remove carb top, remove slide.
nothing happens, it still idles fine if everything is set up right
socrace
New Member
Crazypj, that's not always true.
Most CV slides "bounce" at idle, feeding some extra fuel in the process. Look for yourself, its easily visible. There are some carbs with heavy slides that don't of course, british strombergs for example.
A common Ninja 250 problem is where it will suddenly jump from idle to a high rpm and hang there if the idle circuit is lean.
This happens because the CV slide bounces, it suddenly runs richer, all cylinders start firing, and it hangs there (with the slide partly open).
The op's Kawasaki may be doing this. If so, try running a thin guitar e string through the carb's idle circuits to clear things out.
Most CV slides "bounce" at idle, feeding some extra fuel in the process. Look for yourself, its easily visible. There are some carbs with heavy slides that don't of course, british strombergs for example.
A common Ninja 250 problem is where it will suddenly jump from idle to a high rpm and hang there if the idle circuit is lean.
This happens because the CV slide bounces, it suddenly runs richer, all cylinders start firing, and it hangs there (with the slide partly open).
The op's Kawasaki may be doing this. If so, try running a thin guitar e string through the carb's idle circuits to clear things out.
crazypj
Split personality, I fake being smart
If the slide is bouncing at idle, the butterfly valve isn't set properly and/or carb sync is off
The slide should NEVER move at idle, the bypass and air bleeds should be supplying all the fuel/air.
On 250 Ninja, they are set up real lean, slightly larger pilot jet allows carbs to work 'properly'
even if slide 'bounces' it shouldn't mave far enough to affect mixture if butterfly is closed, there are drillings either side of plate for transitions
The slide should NEVER move at idle, the bypass and air bleeds should be supplying all the fuel/air.
On 250 Ninja, they are set up real lean, slightly larger pilot jet allows carbs to work 'properly'
even if slide 'bounces' it shouldn't mave far enough to affect mixture if butterfly is closed, there are drillings either side of plate for transitions
The slides appear to be rock solid, they stay all the way down while at an idle.
socrace
New Member
Interesting problem you got there Millennium Falcon!
I solved a similar problem with our Ninja 250 after following many forum threads, many of which ended with "bike sold".
Why a lean idle circuit can cause rpm to jump 3krpm (with no throttle change) is still open to debate apparently, although everyone agrees that it happens. A similar issue is probably the more common "hanging idle" effect on decelleration, caused by lean slow circuit.
I solved a similar problem with our Ninja 250 after following many forum threads, many of which ended with "bike sold".
Why a lean idle circuit can cause rpm to jump 3krpm (with no throttle change) is still open to debate apparently, although everyone agrees that it happens. A similar issue is probably the more common "hanging idle" effect on decelleration, caused by lean slow circuit.
