How to install an R6 throttle tube in the Kawasaki Ninja 400 / Z400
Like all stock bikes, the throttle throw on the Kawasaki Ninja 400 is painfully long, and requires twisting your arm to awkward angles to reach full throttle without re-gripping the throttle. Not only is this a nuisance, but it’s dangerously distracting while trying to ride.
A quick and inexpensive way to shorten the throttle throw is to replace the OEM throttle tube on your Ninja 400 with one from a Yamaha R6, which has a larger cam diameter and thus, reduces the distance you have to twist the throttle before you are wide open. You can find the replacement throttle tube here. We also have the matching grip for the left side. A nice little upgrade to your bike without having to install an expensive full race throttle system with new cables.
I’ve seen some confusion online about which throttle tube to use. It seems people think that you should use an older generation R6 throttle tube because it fits without modification, but that’s actually a waste, because it’s about the same size as the OEM Ninja 400 throttle tube. So of course it fits, but it doesn’t change anything.
You’re better off using a newer generation R6 throttle tube, which is what we sell here because it has a larger diameter cam. However, there’s a small interference in the housing that you must address first, so you don’t have any issues. There is a tiny area of the plastic housing that must be filed/grinded/sanded down to increase clearance for the cable, then the installation is easy.
Follow these directions:
Make sure your throttle action is smooth and the throttle snaps back when released.
2 Comments to “ How to install an R6 throttle tube in the Kawasaki Ninja 400 / Z400”
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I tried this mod in my ninja 300 without the dremel part and the throttle didn’t snap back smoothly.
Will simply filing/dremel on that corner help?
And will my OEM throttle work after filing down the corner?
You may need to do the same dremeling as with the 400, and yes your stock throttle will work. Be sure you also have your throttle properly adjusted and cables routed correctly as well, and there are no other clearance issues with the grip or tube. As always, we recommend professional installation of all parts.