ninjette.org - View Single Post - New 250 owner. Idle hangs at 4,000 rpms. Carb issue?

anarchyx34 · August 30th, 2015, 07:07 AM

So I just picked up a 2004 Ninja 250 for really cheap. The only issue with the bike is that it wants to idle at 4,000 rpms. Firstly it's a little difficult to start, and I need to use the choke all the way on. After it warms up if I try and completely disengage the choke, it wants to stall. So I played with the idle knob and got it settled to about 1200 rpms. If I blip the throttle, it'll hang at 4k. The only way to get it back down again is to play with the idle knob. Also there's a very fine line between it stalling and revving to 4k as I adjust the knob. I tried bogging the engine against the clutch to see if it would settle down to 1200 rpms by itself but it just goes right back to 4000.

I have a bill from a shop stating that the carbs were cleaned/adjusted and apparently re-jetted earlier this month. The PO said that this is how he got it back from them. He wasn't very mechanically inclined so I don't think he realized that it wasn't right.

As far as myself, this is my first motorcycle but I've got over 10 years of experience as an auto mechanic. Unfortunately my experience with carburetors is somewhat limited. My gut instinct right now is to just buy another un-molested carb and throw it on and see what happens, but I'm hoping some of you might have some pointers for me.

Thanks!

August 30th, 2015, 07:07 AM	#1
anarchyx34 ninjette.org member Name: Joe Location: Brooklyn, NY Join Date: Aug 2015 Motorcycle(s): 04 EX250 Posts: 30	New 250 owner. Idle hangs at 4,000 rpms. Carb issue? So I just picked up a 2004 Ninja 250 for really cheap. The only issue with the bike is that it wants to idle at 4,000 rpms. Firstly it's a little difficult to start, and I need to use the choke all the way on. After it warms up if I try and completely disengage the choke, it wants to stall. So I played with the idle knob and got it settled to about 1200 rpms. If I blip the throttle, it'll hang at 4k. The only way to get it back down again is to play with the idle knob. Also there's a very fine line between it stalling and revving to 4k as I adjust the knob. I tried bogging the engine against the clutch to see if it would settle down to 1200 rpms by itself but it just goes right back to 4000. I have a bill from a shop stating that the carbs were cleaned/adjusted and apparently re-jetted earlier this month. The PO said that this is how he got it back from them. He wasn't very mechanically inclined so I don't think he realized that it wasn't right. As far as myself, this is my first motorcycle but I've got over 10 years of experience as an auto mechanic. Unfortunately my experience with carburetors is somewhat limited. My gut instinct right now is to just buy another un-molested carb and throw it on and see what happens, but I'm hoping some of you might have some pointers for me. Thanks!