35 Hours On The 2019 Kawasaki KX450


Primary Use: Riding local SoCal motocross tracks

Main Mods: Dunlop MX33 tires, ODI Flight bar (McGrath bend), Ride Engineering 1-1/8-inch one-piece bar mounts, and one-rate-stiffer fork springs

Moment of Glory: Enjoying Kawasaki’s new hydraulic clutch

Forgettable Experience: Stalling the bike in corners due to the rear brake being way too sensitive, which can partially be attributed to the oversize 250mm rotor

Hours: 35

Aftermath: Three sets of Dunlop tires, one set of Dunlop heavy-duty tubes, one OEM clutch, and one set of OEM rear brake pads

Over the first few months of riding and testing the new 2019 450 motocross bikes, an overwhelming majority of test riders chose the Kawasaki KX450 as their favorite bike. If you are a Kawasaki fan, you are probably saying, “Well, of course it’s the best bike.” However, on paper, it had a previous shootout record of finishing off the podium for a few years. For 2019, it was a completely new model and, typically, with that comes a few bugs to work out before the bike reaches its full potential.

By winning Dirt Rider’s 2019 450 MX Shootout and several other media outlets’ as well, the all-new KX450 did what is equal to a driver winning the Daytona 500 in the first year they qualified. Clearly, you have a good performance package, but now all eyes are going to be on you to see how you hold up over the long haul.

The KX450 is a good bike in stock form. It’s comfortable to ride, the engine is strong across most of the powerband, the suspension settings are neutral and suit most riders, and overall it’s a fun bike to ride. It does come in a touch heavy on the scales, but that weight is not noticeable when riding. If you score an “A” in most categories, you’re bound to be at the head of the class.

The question is, what’s it like after the “new” wears off? In the past, the Kawasaki has had some durability weaknesses in comparison with some if its competition. Have they improved in those categories? In an effort to answer this question, this testbike was handed off to a few different testers over this period to give it a well-rounded usage report. With 35 hours on our testbike, we can say there are some improvements.

We went through one clutch, two sets of rear brake pads, two front tires, three rear tires, and, as of this update, it is in need of a chain and sprockets. The seat foam is becoming a little too “comfortable,” or soft, and could perhaps use an upgrade. Of course, we did a few oil changes and cleaned the air filter numerous times. Overall, this is a decent midterm report card. We have only made a few smaller mods in an effort to personalize the bike. There are no areas that stand out that need serious and immediate attention.

With the EFI mapping, we tested several custom maps provided by Kawasaki along with the preprogramed maps that are available by changing the EFI coupler. The KX450 comes stock with a green coupler and has two optional ones, black and white, which are included when you purchase the bike. These are quick and easy options that can be changed depending on track conditions. The white coupler will give the bike a livelier and quick-revving character while the black one gives it a torquey, slower-revving feeling. Most test riders preferred switching from the green, with about a 50/50 split on white over black.

Our next mod was more for personalization with a lower handlebar, and we went with an ODI Podium Flight McGrath bend bar. Most riders 6 feet and taller thought the stock bar height was comfortable, but shorter riders felt they were a touch high. With the ODI bar, we did have to switch to a 1-1/8-inch bar mount and decided to go with Ride Engineering’s one-piece rubber bar mount, which is still very lightweight and offers good torsional resistance in the event of a crash. We mounted the bar in the stock position with the rear hole facing forward. The ODI bar made the rider position more suitable for shorter riders and made it easier to get over the front of the bike. The flex felt about the same as the stock 7/8-inch Renthal 997 bar.

Another preference modification was ODI MX V2 lock-on half-waffle soft-compound grips. In addition to being softer than the stock grips, they are much easier to install as removing the stock grip from a Kawasaki throttle tube is a time-consuming task and practically requires a 6-inch angle grinder.

The final mod for the time being was a more significant one—stiffer fork springs. The KX450 suffers from diving a little in the front and can really blow through the stroke on bigger impacts. The one-rate-stiffer springs were a quick Band-Aid fix that improved the handling. We played with clickers along with high-speed compression adjustments on the shock, but have not found a perfect setting yet.

Of all the changes Kawasaki made to the KX450 for 2019, the one that seemed to be negative was increasing rear brake rotor size to 250mm. The rear brake is just a little too touchy, and if you rest your foot on the brake, you can find yourself locking the rear far too easily. The result is that it can affect cornering and, if you are not careful, you will stall the bike. We haven’t come up with a solution to this problem yet, but we have considered switching back to last year’s rotor, which would require us to replace the caliper carrier to have the correct fitment.

It’s time to dig a little deeper into how we can make this KX450 into a full race-ready machine. Our wish list of mods going forward are: a full suspension revalve, a gearing change (most likely up one tooth in the rear), and possibly an exhaust system that can help shave a few pounds off the rear of the bike. In turn, we hope to improve engine performance, cornering, and handling so that we can attack the track even harder.

Be sure to check back in a few weeks once we get some more updates and mods on it. If you are thinking about purchasing a KX450 or have already bought one, we will try and point you in the right direction when it comes time to personalize your own green machine.