2012 Kawasaki ninja 250r

[Dallas]

I recently bought a 2012 Kawasaki ninja 250r and it wouldn’t start without the throttle open. I bought a new carburetor for it as well as spark plugs, checked for vacuum leaks. Now my problem is when I get it to start and rev it up the rpm will drop when I let go of the idle but kind of hang at 3000rpm and then slowly drop down and either die or it will drop lower than 1300 I’ve adjusted the idle and everything I’m stuck and don’t know what to do next any suggestions?

[tgold]

Dallas! Glad to have you aboard...

[Triple Jim]

Hello Dallas, welcome!

Are your new carburetors original Kawasaki parts, or aftermarket?
Are your valves in adjustment? They can cause RPM hanging after revving.

[Dallas]

Originally Posted by Triple Jim

Hello Dallas, welcome!

Are your new carburetors original Kawasaki parts, or aftermarket?
Are your valves in adjustment? They can cause RPM hanging after revving.

The new carburetor is aftermarket. I bought another ninja 250 for parts and I rebuilt that one because I had bought a kit. Put that carburetor in mine and now I’ll rev it up and then it’ll drop to 4000rpm and then die as if the kill switch was pressed. Also the screws on the bottom of the carburetor is 1.5 turns out. Sorry I’m new to the motorcycle world so I’m trying.

[ducatiman]

suggest opening the idle adjust screws out to 2 1/2 to 3 turns. Adjust while bike fully hot/warmed up, wear gloves or other protective gear. Reset idle as required. Provided idle jets and associated openings are clear, you should achieve success.

[Dallas]

Originally Posted by ducatiman

suggest opening the idle adjust screws out to 2 1/2 to 3 turns. Adjust while bike fully hot/warmed up, wear gloves or other protective gear. Reset idle as required. Provided idle jets and associated openings are clear, you should achieve success.

Okay so I did turn the screws out more. Tried it with the new used carburetor and the brand new one. So I’m pretty sure it’s only running on one cylinder from what I’m understanding. I changed the spark plugs and coils but when I unplug the right spark plug there’s no change. When I unplug the left one it dies. Anymore suggestion on what I could or should do?

[ducatiman]

please provide total mileage for further suggestions

[CaliGrrl]

Welcome to motorcycling! I hope you find your trouble soon and get your pretty bike on the road.

[Triple Jim]

Originally Posted by Dallas

The new carburetor is aftermarket.

Aftermarket carburetors are very difficult to get working properly.

I bought another ninja 250 for parts and I rebuilt that one because I had bought a kit.

Carb rebuild kits are notorious for containing incorrect parts.

You need to determine whether you have spark at both cylinders. If you disconnect the cables from the spark plugs and connect them to spare plugs, then lay the plugs on the head so they're grounded, you should see both plugs sparking when you crank the engine. Alternatively you can take out the two plugs from the head and use those for the test.

[Dallas]

Originally Posted by Triple Jim

Aftermarket carburetors are very difficult to get working properly.



Carb rebuild kits are notorious for containing incorrect parts.

Update. I ended up making the decision of getting rid of the ninja. I now have a 2012 Honda cbr 250 and I love it 😊. Thank you for the suggestions!!

[Triple Jim]

Good luck to you and enjoy the Honda, and thank you for concluding the thread. Who knows, we may end up with someone else asking for help about that same Ninja.