Mc Garage

2017 Kawasaki Z125 Pro MNNTHBX Intake and Bazzaz ZFi Fuel Controller Install and Dyno Test Video

The little Z finally breaks into double-digit horsepower!

July 8, 2016

When we last checked in we had just installed a DCR high-lift camshaft (click here for the DCR cam install and dyno video) in the little Z125. That mod was surprisingly easy, but it left us with mixed results: More peak power, but an eviscerated midrange. I postulated that the cam couldn’t really perform it’s best with the restrictive stock airbox in place and the standard allotment of fuel from the ECU, so promised to upgrade the intake and fueling and give it another go.

MNNTHBX (it's a tongue-twister of an abbreviation for "Man In The Box") stepped up and sent us its "Mtake" intake system, which consists of a slick tapered silicone hose topped with a K&N-style cotton air filter. Greg at MNNTHBX (mnnthbx.com) is proud to point out that the whole setup is made entirely in the US of A.

The Mtake goes for $99 and like most things on the simple little Z, is easy to install. The stock airbox comes off with three bolts (you also have to temporarily remove the horn) and then the Mtake bolts up and tucks in behind the right fairing shroud. There’s nowhere for the crankcase breather to go (it plugs into the stock airbox), so I just routed it up under the tank until I can put a proper filter on it.

Greg’s “Mtake” is absurdly easy to install and very well designed. A one-bolt bracket secures the air filter behind the right-side fairing where it’s somewhat protected from the elements. Ditching the stock airbox yields another bonus—easier access to the intake valve.©Motorcyclist

For fueling we got a ZFi from Bazzaz, also available through MNNTHBX for $298. Given that the last ZFi I installed was on an insanely packaged V-4 with two injectors per cylinder, plugging the system in on the Kawasaki was a piece of cake! Seriously, I had both the Mtake and the ZFi installed and the bike back together and running in an hour flat. Man I like working on simple bikes!

So, now for the results, and they’re good. With the cam and pipe we were at 9.76 horsepower and 6.46 lb.-ft. of torque. Now we’re at 10.27 horsepower and 7.05 lb.-ft. of torque. Those are the peak figures—the current setup is also stronger in the midrange. In fact, it’s making more power from 5,200 rpm all the way to redline. True, power is still sagging in the bottom of the rev range, but the Z never spends any time there. Check out the dyno chart below.

Red is stock, green is with the Yoshimura RS-2 Mini exhaust, yellow is with the exhaust and DCR cam, and blue is with the pipe, cam, Mtake, and ZFi fuel controller. The horsepower curve is looking beautifully flat up top and the torque curve is flattening out nicely. Hopefully we can clean up that dip at 6,500 rpm with a refined fuel map.©Motorcyclist

So, where to next? For starters we need to build a proper fuel map for the existing setup (we’re running Bazzaz’s base map, which was designed for just the Yoshimura RS-2 Mini exhaust), but then it’s onward and upward. There are still more engine mods to do (BIG BORE?!) and of course loads of fun cosmetic and ergonomic adjustments to tackle, so stay tuned.