TUNED: 2023 Kawasaki KX450X Project Bike Build

The Green Dragon

Story and Photos by Trevor Hunter

The KX450 has been highly rated by us for years, dating back to 2019 when this generation bike first came out. Flash forward to the release of the X off-road model, and Team Green made a step back into their off-road roots. You can read the full Bike Test HERE, and check out why and how it won our 2023 450 Off-Road Shootout HERE, but this bike has a really solid base and in testing this bike in nearly every condition over the last 7-8 months, we settled on this setup.

TCS Powersports is one of our go-to shops for suspension for a few reasons. One, the stuff works well. Plain and simple, if we didn’t feel good about it, we could and would very easily go somewhere else and get free suspension work. However, Todd has some pretty good settings for just about everything and if not, is usually able to build something good based on our comments, which also leads to our next point. In addition to the suspension performance, TCS has spent many days in the desert, at the track, and even at races tearing down suspension and making whatever changes we think we need to make the bike work that much better.

As you can read about in our Bike Test, the stock KX450X suspension isn’t all that bad in the right terrain, but for what we wanted to do with this bike, it was lacking. With high level riders aboard the bike and a primary focus on West Coast GP racing, we needed to go much stiffer on both ends so we could charge harder and further into the nasty braking bumps and bottomless sand whoops that we’d encounter at the races. Bumping up the fork springs (from 0.49 to 0.50 kg/mm) and shock spring (5.3 to 5.4 kg/mm), as well as using Showa A-Kit Spring Seats to go with the stiffer valving setup, we got the suspension working really well to combat the National Grand Prix Championship and other local SoCal GP’s. It has much better hold up, offers better comfort and control, and is a more versatile setup that we can take to the desert, GP’s, moto track, and mountains and still work well.

The next best mod we made to the bike is an ECU reflash by Precision Concepts Racing. The same one that most all of their riders use, from Zach Bell to the old timers, the map smooths out the jerky initial throttle response, making it easier to ride through corners and at slower speeds while ramping up with a progressive power band that revs out seemingly forever. The remap broadens the power with a hard pulling yet easy to ride delivery that hooks up and goes. The KX motor in general likes to be ridden more aggressively and this Precision Concepts map is the same, just in a more controlled way.

The next best mods come in the chassis arena. You can read our Product Test HERE, but the Ride Engineering Performance Link Arm helps the chassis a lot. It drives through acceleration bumps better, staying planted and finding traction, while also helping calm the rear end on decel. With the link arm, we ran 103-105mm of sag depending on the track and the conditions. Another Ride Eng product, and very much so one of the best mods for this bike, is the locking Wheel Spacers. The stock spacers don’t have a lip and immediately fall out when removing/installing the wheels so these are a nice touch that go a long, long way when working on your bike.

Another big one is triple clamps. With the stock clamps, the KX has a vague front end on corner entrance and through the corner, making it hard to really trust the front end when cornering. This wasn’t something we really picked up on until we tried an aftermarket clamp, but once we did we could never go back. We tried a few different clamps and all had similar results, but we settled on this X-TRIG ROCS Triple Clamp with the PHDS Bar Mounts. It softened the initial feel of the suspension, making it less harsh and offering a better feel for the ground beneath you, while also giving us a more precise feel when entering and riding through corners. Overall, this is a big change and tremendously helped the bike, though it can be costly. Lucky for you, since this is an “OEM” part on the KX450SR, the clamps and bar mounts can be purchased on Rocky Mountain ATV/MC for ~$550 HERE. (Clamp Part # 99969-3880 / Bar Mounts Part # 99969-3881) 

Like the ECU mapping, the Pro Circuit exhaust made very similar changes to the powerband, further helping smoothen out and broadening the power. The exhaust coupled with the ECU changes made for a very fun motor to ride. It likes to be ridden hard, almost 350-esque, but it still has that 450cc grunt and torque that you want. It’s also a very fast combo and has pulled a lot of good starts against some heavily modified bikes. 

Those five items are the biggest modifications (and some of the most expensive) made to the bike, but there’s still a plethora of other details to cover. New for us is a Precision Racing Products Steering Stabilizer. Unlike most stabilizers out there, this parabolic unit mounts to the handlebars and not the triple clamps or bar mounts. In doing so, it retains the stock bar height and is very easy to install. On the track, it works really well. Most riders don’t feel they even have a stabilizer on the bike, except they don’t experience any head shake or sudden jolts in the handlebars when hitting something unexpectedly. In short, we get all of the benefits of having a steering stabilizer without many of the downsides.

For handlebars, we’re running Pro Taper ⅞” CR Mid Handlebars. The ⅞” handlebars give us some flex and comfort out of the front end, and the CR Mid bend has a really nice bend to it that most of our testers, big and small, get along with.

Sunstar freshened up the drive train with 13/50 gearing (same as the MX model, -1 out back from the X model stock), as this is our best GP gearing setup. If we’re going to the desert, 13/47 is our go-to as it has enough on the top end while still being just low enough for the technical riding. For the mountains, 13/51 or 13/52 gives us the low end grunt and torque we need to lay off the clutch.

TM Designworks’ Slide-N-Guide Kit does the heavy lifting around the swingarm, far outlasting the stock Kawasaki components. This Baja Endurance Slide-N-Guide Kit is nearly indestructible, and we’ve gotten nearly 500 hours out of one of these chan guides – yeah it’s tough.

The KX doesn’t come stock with an oversized tank so an IMS 2.8 Gal Fuel Tank is a necessity for both racing and riding off-road. In fast desert racing conditions, we can comfortably go ~60 miles on a tank of fuel, and even longer when the speeds are down.

The Corner Coach has quickly become one of our favorite track day tools, especially on a 450, and we’re even using it more and more for off-road riding and racing. It helps alleviate some of the upper body abuse and keeps us in the right position when cornering. 

Acerbis outfitted our bike with a complete plastic kit, including the Skid Plate, Radiator Louvers, Mud Flap, etc. The stock Kawasaki plastic is on the brittle side and prone to cracking and breaking, but the Acerbis product is as good as it gets. The fit and finish is second to none and a new set of plastic goes a long way in rejuvenating a bike’s look and feel. The skid plate we are using is actually for the 2016-2018 KX450, a tip we got courtesy of the Precision Concepts Kawasaki Race Team. Unlike the one designed for this bike, the older skid plate uses the frame mounting tabs and bolts directly to the bike. A slight modification is needed as you have to shave off some plastic to fit around the water pump, but it offers a little more coverage than the new skid plate and is easier to mount.

DeCal Works made the bike pretty with a cool graphics design. Where the DeCal Works graphics really shine is on installation. It takes some effort to put an air bubble in these graphics, they install that easily. We’ve also used them in the past and they go the distance and look good while doing it.

Dunlop provided the tires with a MX53F/AT81 tire combo. The MX53F is one of our go-to tires for off-road and really just about any summertime riding in SoCal. We prefer it more over the MX33F when the dirt hardens up as it’s more consistent and has better traction in the corners. Nitromousse Foam Inserts stuff the tires to keep us flat free for a long, long time.

With the stock battery, we’d run into trouble at times when practicing or doing dead engine starts – particularly when it was cold outside. For the most part, it’d fire pretty quick but occasionally the bike would be lifeless when trying to start the engine multiple times in a row. To combat this, we went with the proven Fire Power Li-Ion Battery. Now, the bike starts almost too quickly most of the time, and we never have to worry about sitting helpless on the start line or on the trail. 

The stock KX front brake lever is atrocious, almost like squeezing a thin razor blade, so we equipped our 450X with an ARC lever for a nicer touch to the finger.

Bullet Proof Designs Rear Disc Guard is beefy, yet lightweight and does a good job of protecting the rear rotor from destruction. 

There are a few big ticket items here that really transform the bike, while others are personal preference or are just upgrades over worn out stock components. But this bike is built as a package and there is really no “fluff” on this bike. Even the shiny parts like the Slide-N-Guide Kit and Disc Guard add some value, especially in a long term way.

Do You Like DBT Bringing You Fresh Content? Search and Shop Through the Links Above or Below:

Leave a Reply

Protected by WP Anti Spam