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Bob KellyIII · May 12th, 2023, 04:05 PM

I took a few days off from the ninja out of necessity.... she was getting to me !
so after a break I went out there today and fired it up and it ran like doo doo.....
had a big flat spot in mid range and didn't want to get past it.... so I figured I would let it warm up while I put back on the water reservoir... after a few minutes idling there she started acting better.... the flat spot was almost gone.... reached down and put my hand on the cylinders and they were barely warm at all.... so I figured it needed to warm up more..... I piddled around and did a few other things and decided to put the air cleaner back on the back of the carbs.... from that point on it ran great.... evedently it NEEDS some restriction to run properly !!!! .... burrying the throttle at idle got it to rev to 9k rpm without a hint of flatness in mid range then.... then I noticed the idle was right at 2k RPM so I lowered it a bit to around 800 RPM.... tested it a few more times to 9k RPM and it never balked once perfect every time.... this bike has to be warm to run right !
so I turned it off and started putting it back together properly....
my plan is to get it all the way back together except the fairings and then go take it for a good ride... and see how it reacts under a load..... i think it will be fine although it might be soft on acceleration around mid range but as long as there is no flat spot I am going to call it good enough ! .....
I will wait to do a plug color check till after a good run as it will give me a false reading doing just stationary stuff...
.... My Conclusion is this.... this bike is designed to run so lean to meat California's EPA crap that if you change the exhaust muffler you will screw it all up ! god forbid if you change the air box or anything else the muffler alone is enough to cause you grief !
I think they Very Poorly designed the carbs simply because they are so hard to clean and get them actually clean... so extream methods have to be used to get them clean
and then there is the mid range issue.... if the air screws are adjusted too lean
it will have a flat spot at mid range..... ( so if you have a flat spot in mid range after cleaning your carbs look there first... these are not set them by factory specks and your done with them) personally I think the slow speed jets in the carbs may well be too small on this bike.... which may well be the biggest cause of the problems with the air screws too. but they should be stock...the main jets were, so it's a logical conclusion that no one has changed them in the past.
that and my Altitude probably add to the problems as you go up in altitude there is less barometric pressure to help push the fuel through the jets... this means they should be a tad bigger.... to work the same as at sea level.
I think the 2012 Kawasaki Ninja 250R is a marval of engineering in and of itself However they cut it so fine that the fuel air ratio going in to the cylinders is balanced on a razor's edge..... add a flow through muffler to the mix and you tip it over the razors edge into having problems like flat spots .... that is pirty bazaar if you ask me !
I have never ran into this kind of a problem with any other bike in my life... and if this is what new technology offers I don't want it ! it's too finicky !.....
having learned about this bike through this proccess and all I did was do a valve check and have the carbs cleaned by someone that Knows what they are doing .... and them all these problems crop up.... it's probably the first time the carbs have been truely clean sense the bike was sold..... but such a simple task that has taken almost 4 months to fix is silly beyond words.... no bike is worth that ! not even a ninja !
so I will probably sell the little monster in the near future while the carbs are still clean
....because I do not want to have to work on that thing I enjoy working on bikes but that one you can't work on it easily.... there is no room to work on anything on it
it takes 2 men and a small boy just to get the carbs Out..... it's silly when I can have the carbs off the Triumph 750 in 10 minutes while it takes a day just for me to get down to them..... on the ninja ..... so I have come to the conclusion although it is a great bike it is Not for me.... I do think I will sell it !
.....
Bob.......

May 12th, 2023, 04:05 PM	#88
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 took a few days off from the ninja out of necessity.... she was getting to me ! so after a break I went out there today and fired it up and it ran like doo doo..... had a big flat spot in mid range and didn't want to get past it.... so I figured I would let it warm up while I put back on the water reservoir... after a few minutes idling there she started acting better.... the flat spot was almost gone.... reached down and put my hand on the cylinders and they were barely warm at all.... so I figured it needed to warm up more..... I piddled around and did a few other things and decided to put the air cleaner back on the back of the carbs.... from that point on it ran great.... evedently it NEEDS some restriction to run properly !!!! .... burrying the throttle at idle got it to rev to 9k rpm without a hint of flatness in mid range then.... then I noticed the idle was right at 2k RPM so I lowered it a bit to around 800 RPM.... tested it a few more times to 9k RPM and it never balked once perfect every time.... this bike has to be warm to run right ! so I turned it off and started putting it back together properly.... my plan is to get it all the way back together except the fairings and then go take it for a good ride... and see how it reacts under a load..... i think it will be fine although it might be soft on acceleration around mid range but as long as there is no flat spot I am going to call it good enough ! ..... I will wait to do a plug color check till after a good run as it will give me a false reading doing just stationary stuff... .... My Conclusion is this.... this bike is designed to run so lean to meat California's EPA crap that if you change the exhaust muffler you will screw it all up ! god forbid if you change the air box or anything else the muffler alone is enough to cause you grief ! I think they Very Poorly designed the carbs simply because they are so hard to clean and get them actually clean... so extream methods have to be used to get them clean and then there is the mid range issue.... if the air screws are adjusted too lean it will have a flat spot at mid range..... ( so if you have a flat spot in mid range after cleaning your carbs look there first... these are not set them by factory specks and your done with them) personally I think the slow speed jets in the carbs may well be too small on this bike.... which may well be the biggest cause of the problems with the air screws too. but they should be stock...the main jets were, so it's a logical conclusion that no one has changed them in the past. that and my Altitude probably add to the problems as you go up in altitude there is less barometric pressure to help push the fuel through the jets... this means they should be a tad bigger.... to work the same as at sea level. I think the 2012 Kawasaki Ninja 250R is a marval of engineering in and of itself However they cut it so fine that the fuel air ratio going in to the cylinders is balanced on a razor's edge..... add a flow through muffler to the mix and you tip it over the razors edge into having problems like flat spots .... that is pirty bazaar if you ask me ! I have never ran into this kind of a problem with any other bike in my life... and if this is what new technology offers I don't want it ! it's too finicky !..... having learned about this bike through this proccess and all I did was do a valve check and have the carbs cleaned by someone that Knows what they are doing .... and them all these problems crop up.... it's probably the first time the carbs have been truely clean sense the bike was sold..... but such a simple task that has taken almost 4 months to fix is silly beyond words.... no bike is worth that ! not even a ninja ! so I will probably sell the little monster in the near future while the carbs are still clean ....because I do not want to have to work on that thing I enjoy working on bikes but that one you can't work on it easily.... there is no room to work on anything on it it takes 2 men and a small boy just to get the carbs Out..... it's silly when I can have the carbs off the Triumph 750 in 10 minutes while it takes a day just for me to get down to them..... on the ninja ..... so I have come to the conclusion although it is a great bike it is Not for me.... I do think I will sell it ! ..... Bob....... __________________________________________________ Its too late when you've gone too far !