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Clutch Slipping, Poor Shifting, False Neutrals, Dropping Gears - Explained & Fixed!

Forgive the delay, I've been working on this article for awhile. It's a lot of information that we've learned and implemented over the past couple years of racing the Ninja 400 in AFM, CVMA, WERA, and MotoAmerica. I hope it helps everyone understand what is going on and how we fix everything so that it's reliable for track or everyday use.

Kawasaki Ninja 400 Clutch Slipping, Poor Shifting, False Neutrals, and Dropping Gears - Explained and Fixed!
 

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Thank you, you did a lot of work for us.

I noted your statement from the linked article: "Kawasaki knows about this issue and supposedly the 2020 bikes will have a modified pull rod from the factory. But if your bike is a 2018-2019 and your clutch begins to slip, you can replace the OEM pull rod with our Ninja400R Race Spec modified pull rod (which has been machined down with the necessary extra clearance) and get another .040″ of wear from your clutch plates before they will need to be replaced."

Has there been any indication from Kawi that this will result in a recall and replacement of the pull rod for 2018 & 2019 models?
 
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Discussion Starter #3
Thank you, you did a lot of work for us.

I noted your statement from the linked article: "Kawasaki knows about this issue and supposedly the 2020 bikes will have a modified pull rod from the factory. But if your bike is a 2018-2019 and your clutch begins to slip, you can replace the OEM pull rod with our Ninja400R Race Spec modified pull rod (which has been machined down with the necessary extra clearance) and get another .040″ of wear from your clutch plates before they will need to be replaced."

Has there been any indication from Kawi that this will result in a recall and replacement of the pull rod for 2018 & 2019 models?
I wouldn't hold your breath for a recall. But I do expect to see a new part for the 2020 bikes.
 

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I wouldn't hold your breath for a recall. But I do expect to see a new part for the 2020 bikes.
My 2007 Ninja 650R had no engine or transmission issues, and I don't normally buy extended warranties. But the complaints at this site about shifting lead me to buy the extended warranty even though it seemed that the issue may have been isolated to the 2018 model year and I was buying a 2019. Now I'm feeling as if this wasn't a big waste of money. :sad:
 
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Just how common is this problem? From reading that article it would seem that given it is an actual design flaw it would have to be very prevalent. I have added a spring to the clutch cable to help with clutch feel but I still find it hard to launch the ninja like other bikes. It feels to me from a standing start that my clutch actually might slip a little bit when attempting to accelerate hard. Should I be worried? I haven't had any problems with shifting once I get going though.
 

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Thanks for doing a great job of explaining the issues. I changed out to heavier springs and detent spring about a year ago, I always forget how much I love the stiffer springs until I jump on my wife's stock ninja...I guess I need to place another order....I do have to say that both of our 2018 Ninjas have not had a single issue, she with 10,000 miles of brutal Los Angeles commuter miles and me with 4,000 miles of canyon carving (or trying to carve :) )
 
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Discussion Starter #8
Just how common is this problem? From reading that article it would seem that given it is an actual design flaw it would have to be very prevalent. I have added a spring to the clutch cable to help with clutch feel but I still find it hard to launch the ninja like other bikes. It feels to me from a standing start that my clutch actually might slip a little bit when attempting to accelerate hard. Should I be worried? I haven't had any problems with shifting once I get going though.
Common enough that I would say it's surprising if someone reports they have a bunch of miles on the bike without any problems.
 

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Common enough that I would say it's surprising if someone reports they have a bunch of miles on the bike without any problems.
Yes that makes sense, good write up by the way. Is it worth just putting in stiffer springs or am I better off doing springs and wear plates or a complete upgrade. I don't race the bike but I do ride hard on the street and rev the **** out of the little twin. It would be great to have a decent launch too and surprise faster bikes at traffic lights.
 

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Clutch Upgrade

Last week I ordered a set of Barnett Kavalar Clutch Plates, Barnett heavy duty springs, The upgraded Clutch pull rod, and the heavy duty spring for the Clutch cable adjuster on top of the Clutch housing case. And a new OEM Gasket for the Clutch housing from Norton. When it comes in,, I will be installing this ASAP... When I did the Norton ECU upgrade, the Bike has a lot more power and during HARD accelerations and shifting. My OEM Clutch started really slipping and really having BAD Issues... A few months ago before my warranty ran out. I had the Dealer totally rebuild my OEM Clutch and redid all components, plates, springs and everything.. And for a time it did Okay. But when the Bike got beefed up with the extra Power and Torque.. Then it really started to slip once more. Just hope this Clutch Upgrade resolves this slipping Issues once and for all......I will keep everyone posted... And would also add that the WEAKEST point on the Ninja 400 is always been about that Slipping Clutch Issue. I WISH that the Kawasaki Engineers would have got a Clue about this badly needed addressed Issue. Better Plates, Springs, Clutch Rods and Spring on the Adjuster should really be stock with this Machine. But still the Best in the Small Bore Class of Motorcycles...
 
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Discussion Starter #11
Yes that makes sense, good write up by the way. Is it worth just putting in stiffer springs or am I better off doing springs and wear plates or a complete upgrade. I don't race the bike but I do ride hard on the street and rev the **** out of the little twin. It would be great to have a decent launch too and surprise faster bikes at traffic lights.
The most noticeable things for street bikes I would say are the pull rod, heavier clutch springs, and cable springs. If you do these early enough, you can keep the stock friction plates for awhile until they are worn out. The problematic shift shaft doesn't seem to bother some people, or they don't notice it on the street. Same thing with the shift star and detent spring, those are more critical for track bikes.
 

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@Norton-Motorsports.com Jesse, as a street rider and an engineering machinist I'm interested in modifing my clutch pull rod to help prevent any future issues perhaps.
Looking at the picture of your modified pull rod it would appear you have just put it in a lathe and machined that flange back a touch to give more clearance and the diameter and other dimensions are untouched?
How hard is that steel to turn with regular tungsten carbide insert tools?
PM me if you dont want to give away any trade secrets :grin:
 

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The most noticeable things for street bikes I would say are the pull rod, heavier clutch springs, and cable springs. If you do these early enough, you can keep the stock friction plates for awhile until they are worn out. The problematic shift shaft doesn't seem to bother some people, or they don't notice it on the street. Same thing with the shift star and detent spring, those are more critical for track bikes.
Cheers mate.
 

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Jesse,

Feathering the OEM clutch is quite vague actually. Especially at slow speed maneuvers. Like you say, it is brought upon by the "assist" ramp feature of the OEM clutch. Good for beginner riders where stalling can be an issue. And yes, launch control is indeed lacking. Somewhat like an on/off switch.

What I find appealing about the Yoyodyne slipper clutch is the absence of the "assist" ramp found in the OEM clutch for better launch control, and the extra friction plate for added clamping area.

So it brings me to the question: If my stock clutch system is fitted with all your upgrade parts, would it be good enough for your stage 1 power package deal? Would I have to upgrade to a Yoyodyne to compensate for clutch slippage with the added power?


PS, I'm guessing the old penny trick or a gear holder can be used to torque that big 27 mm nut, when no rattle gun or clutch holder is around.
 
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Discussion Starter #15
Jesse,

Feathering the OEM clutch is quite vague actually. Especially at slow speed maneuvers. Like you say, it is brought upon by the "assist" ramp feature of the OEM clutch. Good for beginner riders where stalling can be an issue. And yes, launch control is indeed lacking. Somewhat like an on/off switch.

What I find appealing about the Yoyodyne slipper clutch is the absence of the "assist" ramp found in the OEM clutch for better launch control, and the extra friction plate for added clamping area.

So it brings me to the question: If my stock clutch system is fitted with all your upgrade parts, would it be good enough for your stage 1 power package deal? Would I have to upgrade to a Yoyodyne to compensate for clutch slippage with the added power?


PS, I'm guessing the old penny trick or a gear holder can be used to torque that big 27 mm nut, when no rattle gun or clutch holder is around.
When properly upgraded with the recommended parts, there's no trouble with the stock clutch handling power, we've run 60hp through it just fine. It's just much nicer to have the Yoyodyne for the described reasons and better clutch plate life.
 

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Hi guys,

The biggest gripe I have with my bike is the sloppy gear changes. Sometimes the gear doesn't engage, sort of feels like the gear is blocked, and it needs another go before it goes in (often from 5th to 6th). Sometimes I think I've changed gears but turns out I'm still in the same gear when I release the clutch (often from 2nd to 3rd).

Would you then suggest replacing the shift shaft?
Not sure exactly what the detent spring does in this regard?

Cheers!
 
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Discussion Starter #17
Hi guys,

The biggest gripe I have with my bike is the sloppy gear changes. Sometimes the gear doesn't engage, sort of feels like the gear is blocked, and it needs another go before it goes in (often from 5th to 6th). Sometimes I think I've changed gears but turns out I'm still in the same gear when I release the clutch (often from 2nd to 3rd).

Would you then suggest replacing the shift shaft?
Not sure exactly what the detent spring does in this regard?

Cheers!
Correct, this is exactly what the Blueprinted shaft is for. While you are replacing it, you will definitely want to replace the pull rod and clutch springs. The other parts, shift star and heavy detent spring, are up to your preference. They are all improvements from stock, just cost a little money. The detent spring does help the bike shift more crisply, and it helps reduce false neutrals, but the shift star is more for the false neutrals.
 

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Are the heavy duty springs pretty straightforward / simple to install? I've done the return spring already, I've only had a couple times where the clutch would slip during fast acceleration in higher gears. Might do this at the start of the season and see how it goes.
 
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