ninjette.org - View Single Post - Ninja 250r dying on throttle after carb rebuild

Bob KellyIII · May 24th, 2023, 05:08 PM

I would say YES sync the carbs it may well cure the 9K RPM flat spot.... and make sure the bike is warm when testing it these things are cold blooded and need to be warm !
....
same problem I was having ( might still have ) and all I did was have the carbs professionally cleaned sense I didn't like the idea of having to do it 3 times like I did last time..... this time they are very clean of that I am sure!
My bike was bogging at 5~6000 RPM.... a big flat spot in the RPM Range we discussed it
at length and decided to add 2 shims under the needles as well as lean it out a tad because it was too rich... so we put in 95 main jets.... I doubt that changed anything personally.... ( too small a change from 98 to 95 !) but the shims did seem to change it alot.... when the bike warms up it runs great but when cold it still has a slight bogg around 5~6000 RPM once it is warm it doesn't bogg at all...
you might try one shim under the needles and see if the bogg your getting at 9k RPM goes away as a shim will make it richer !
..... that's my guess I haven't ridden the Ninja yet as I can't find all the bolts now ! AURGH!!!!!
but I did take it out of the shop and she is ready for a run on the street without the fairings on it....
.....
I think the reason this problem croped up was because of the aftermarket exhaust muffler that the previous owner put on it.... it's always ran rich judging by the plug color.... but at other ranges of RPM it felt very lean.... but the Shims seamed to have cured that..... how it ran before I have no idea.
it doesn't make any sense to clean the carbs and have this problem crop up !!!
but it is what it is ! live and learn I guess !!!
.....
Bob.......

May 24th, 2023, 05:08 PM	#6
Bob KellyIII Retired motorcycle Mc. Name: Robert Location: Weed, California. Join Date: Jul 2021 Motorcycle(s): 2012 Kawasaki Ninja 250R, 2021 CSC TT250, 1977 Triumph Bonneville 750cc,2001 Honda XR650L. Posts: A lot.	I would say YES sync the carbs it may well cure the 9K RPM flat spot.... and make sure the bike is warm when testing it these things are cold blooded and need to be warm ! .... same problem I was having ( might still have ) and all I did was have the carbs professionally cleaned sense I didn't like the idea of having to do it 3 times like I did last time..... this time they are very clean of that I am sure! My bike was bogging at 5~6000 RPM.... a big flat spot in the RPM Range we discussed it at length and decided to add 2 shims under the needles as well as lean it out a tad because it was too rich... so we put in 95 main jets.... I doubt that changed anything personally.... ( too small a change from 98 to 95 !) but the shims did seem to change it alot.... when the bike warms up it runs great but when cold it still has a slight bogg around 5~6000 RPM once it is warm it doesn't bogg at all... you might try one shim under the needles and see if the bogg your getting at 9k RPM goes away as a shim will make it richer ! ..... that's my guess I haven't ridden the Ninja yet as I can't find all the bolts now ! AURGH!!!!! but I did take it out of the shop and she is ready for a run on the street without the fairings on it.... ..... I think the reason this problem croped up was because of the aftermarket exhaust muffler that the previous owner put on it.... it's always ran rich judging by the plug color.... but at other ranges of RPM it felt very lean.... but the Shims seamed to have cured that..... how it ran before I have no idea. it doesn't make any sense to clean the carbs and have this problem crop up !!! but it is what it is ! live and learn I guess !!! ..... Bob....... __________________________________________________ Its too late when you've gone too far !