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ZX14R Runs Badly Above 5k RPM Under Hard Accel

11304 Views 23 Replies 10 Participants Last post by  kawabrother1
Hi folks! New ZX14R owner and I'm also a new member here. Recently picked up a used 2014 ZX14R with only 4700 miles on it and have enjoyed learning about it. It appears it’s all stock except for the 2Bros slip-on pipes. I have recently changed the oil, took off the factory tires, and put on two new Mich PR4s.

Today I took it out of traction control for the first time and had it in full power and noticed an issue where it stutters, bucks and kicks very badly above 5k rpm under hard acceleration. So I pulled over, shut it off, and let it sit for about 5 seconds, cranked it back up and did a hard acceleration through first and second and it was fine! No stuttering. Right after that I slowed back down and put back in first gear and got back down on it hard again through first and second and then it went back to stuttering very badly in both gears above 5k rpm. It bucks and kicks so hard it slams me into and away from the gas tank hard. Damn near racked me. Tried the same scenario again: shut it off for about 5 seconds, crank it back up, then run it real hard through 1st and 2nd gears and it has absolutely no stuttering or misfiring on that 1st run. Slow back down to 10 mph or so, put back in 1st gear, punch down on it hard again and as soon as it gets above 5k rpm it starts bucking and kicking violently again. So I took it home and was like: “wtf?” Lifted the seat and poked around at some of the wiring, all looks good. Bike sat for about an hour and I decided to go back out and try it again. For about 15 minutes it was absolutely fine. I did 3 or 4 very hard accelerations through 3rd gear and it ran perfectly above 5k rpm. I mean to tell you that fuggin bike goes in beast mode big time! So I turn around and head back to the house and got down on it one more time and low and behold the issue came back! So I stayed out and rode it around for another 10 minutes and it still completely misbehaves above 5k rpm.

Anyone seen this type behavior before? Or maybe know where to start looking? Maybe remove the battery for a few minutes to reset the ECU? Or is there some other type of reset?

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Pull the tank off pull the fuel pump out take the unit apart and inspect the fuel filter, If it looks crappy clean the filter, Honestly at that point even if it doesnt look that bad might as well clean it. Its happened 2 times on my bike, pretty close intervals. The rpm it stutters at will get lower if you dont clear the filtr. It happend to me when I ran the tank way down past reserve.
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What he said
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Fuel problems generally just show up as soggy power, not hard stuttering. I'd suggest pulling the plugs and having a look there, first. Don't forget there is also a protection mode that can be set off by hard riding, under the right circumstances and it makes a mess of performance. A tune will eliminate this but, before you go there, check the ignition system first.
Simple things first. Most issues are found there.

I once showed up at an event to find an acquaintance ripping the wiring out of his wife's sportbike, bodywork completely stripped, multimeter in hand and scratching his bald head raw trying to figure out why it wouldn't start after being dropped on it's side in the parking lot. I picked up a stray paper clip, shorted the clutch switch and it fired right up.

Getting into the complicated shit first will make you look right past a simple solution.
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Thanks so much for the replies!! I really appreciate your insights. Sorry it took me so long to get back. My mom had a mild stroke Friday night and was hospitalized over the weekend and we finally got her home yesterday. Ugh.

I'll start with the fuel pump/filter assy. Power comes right back as you reduce throttle which would make sense if it were a limited fuel flow problem. If not that I'll jump over the spark plugs after that. Neither procedure looks very easy to perform but I need to get my feet wet on this bike.

Again, thank you for the help!
Hope your mom is recovering .
Youll find those 2 jobs are easy .
Just dont pinch the wires when u put the tank back on.
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I'm not saying this is your issue, but the with the 14R, if you crack the throttle hard it can go into limp mode.
limp mode.
Whoever put that on a 1400+cc engine should have their man card revoked and their nuts summarily lopped off with a butter knife.
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their nuts summarily lopped off with a butter knife.

:lol
Fuel problems generally just show up as soggy power, not hard stuttering. I'd suggest pulling the plugs and having a look there, first. Don't forget there is also a protection mode that can be set off by hard riding, under the right circumstances and it makes a mess of performance. A tune will eliminate this but, before you go there, check the ignition system first.
When it happened to me, I chit you not.
it bucked hard like a horse
Thanks so much for the replies!! I really appreciate your insights. Sorry it took me so long to get back. My mom had a mild stroke Friday night and was hospitalized over the weekend and we finally got her home yesterday. Ugh.

I'll start with the fuel pump/filter assy. Power comes right back as you reduce throttle which would make sense if it were a limited fuel flow problem. If not that I'll jump over the spark plugs after that. Neither procedure looks very easy to perform but I need to get my feet wet on this bike.

Again, thank you for the help!
Its not that bad, first time it took me about two hours, the second time just under an hour.
2
Pull the tank off pull the fuel pump out take the unit apart and inspect the fuel filter, If it looks crappy clean the filter, Honestly at that point even if it doesnt look that bad might as well clean it. Its happened 2 times on my bike, pretty close intervals. The rpm it stutters at will get lower if you dont clear the filtr. It happend to me when I ran the tank way down past reserve.
What he said
Ok. Great tip y’all. Finally got into it. And the fuel filter was really clogged up with what looks like corrosion (grey metallic looking junk). See photos below. Coincidentally when I first got the bike in February the gas cap was really hard to open and I was worried about bending the damn key it was so hard to turn! There was a lot of surface corrosion on all the internal aluminum gas cap parts under the lid. So I took it apart, cleaned it up, greased the parts up real well, wiped off the excess, slapped it all back together, works great now, and didn't think another thing about it.

Background: The previous owner was a 70 year old dude that only put 800 miles a year on it and never rode it in the rain. The bike is showroom condition under the seat and inside the fairings – and I’m like: “hell yeah!” But I guess it sat in his garage with significant moisture in the gas tank for those four years and that’s where all the corrosion came from and now it’s all shitted up in the fuel filter.

So the service manual says:
“The fuel filter is built into the pump and can not be cleaned or checked.”
And
“If the fuel filter is suspected of clogging or being damaged, replace it with the fuel pump as a set.”

Where can I find a replacement fuel filter? Bike Bandit and the other OEM parts houses only show the fuel pump as an assy.

I will also have to clean out the gas tank real well before putting it back together.

.

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I'm pretty sure this is the fuel filter you need.
[ame]https://www.amazon.com/Kawasaki-Filter-Brute-Force-49019-0013/dp/B00OJB4QX8[/ame]
That does look like it!

I also just found this ZX14R Fuel Filter on eBay

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The new eBay fuel filter came in yesterday so I reassembled everything and it runs beautifully now under full load. I washed out the gas tank with acetone and there was more of that grey aluminum corrosion crud inside the tank.

Closer inspection shows the gas cap internal parts continues to corrode (and bind again) even after I disassembled and greased everything in February. It is already getting hard to turn the key again.

Looks like I will have to replace the gas cap to prevent this from happening again.

.
I have one in a box if you want to go back to stock. I removed it and replaced it with a screw-in cap, which is what I would advise you to do. The stocker I removed functioned perfectly, I just think the idea of a locking gas cap is ludicrous.
I have one in a box if you want to go back to stock. I removed it and replaced it with a screw-in cap, which is what I would advise you to do. The stocker I removed functioned perfectly, I just think the idea of a locking gas cap is ludicrous.
Thanks for the offer but I agree with your advice on going to a non-locking type cap. eBay & Amazon have a few nice CNC units to choose from.

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The new eBay fuel filter came in yesterday so I reassembled everything and it runs beautifully now under full load. I washed out the gas tank with acetone and there was more of that grey aluminum corrosion crud inside the tank.

Closer inspection shows the gas cap internal parts continues to corrode (and bind again) even after I disassembled and greased everything in February. It is already getting hard to turn the key again.

Looks like I will have to replace the gas cap to prevent this from happening again.

.
My key gets boggered up too. I just keep putting 3 in 1 oil in it once in a while and that keeps it moving freely
My key gets boggered up too. I just keep putting 3 in 1 oil in it once in a while and that keeps it moving freely
Excellent point. Mine needed the lock to be oiled too. But the majority of the binding in my cap assy is due to the corrosion in and around the 2 lock pawls and their internal springs. They cannot move freely b/c the constant shedding of the gray corroded aluminum.

In my post above I mentioned cleaning and greasing the pawls but I shouldn't have used grease. Instead I should've applied a material like Corrosion-X so I ordered some of it. It's an anti-seize, penetrant, lubricant.

[ame]https://www.amazon.com/Corrosion-X-Corrosion-Technologies-91002-Corrosionx/dp/B0009GYRWW/ref=sr_1_2?ie=UTF8&qid=1524630956&sr=8-2&keywords=Corrosionx[/ame]

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