What is it about a project bike that makes the MXA wrecking crew drool like kids in a candy store? Maybe it’s the endless possibilities. Perhaps it’s the list of trick components that litter the bike. Maybe it’s the allure of testing one company’s vision of the perfect motocross weapon. Regardless of the reasoning, we’re always eager to sling a leg over a purpose-built project bike.

In recent years, Wiseco has provided plenty of exhilaration for the MXA gang. Not only have they crafted race steeds for our review, but we have even spent time at their home offices in Mentor, Ohio, doing some testing. Exactly two years ago to the day, MXA tested Wiseco’s race-ready Yamaha YZ450F. One year ago, we made the pilgrimage back to Ohio to sling a leg over their 2010 Honda CRF450.

It’s no secret that the MXA wrecking crew doesn’t like to test motorcycles outside of our controlled climate in SoCal. Not only does Southern California have perfect weather for testing, but we are so familiar with the lay of the land at Glen Helen, Piru, Gorman, Racetown, Cahuilla and Competitive Edge that we can tell fast from slow within a couple of laps. These tracks are our dirt dynos. So, when Wiseco buttoned up their project Kawasaki back in Ohio, we weren’t looking forward to dodging airport security, wearing long underwear to ride and freezing our appendages in the cool Ohio winter. As luck would have it, Wiseco didn’t really feel the need to have us run wild through their production facility and worked out the logistics to deliver a freshly tuned 2012 Kawasaki KX450F to MXA‘s palatial headquarters in Valencia, California.

In celebration of their 70th year in business, Wiseco built MXA a 2012 Kawasaki race bike. Better yet, they addressed key problems on the green steed.

It’s easy to understand why Wiseco targeted the 2012 Kawasaki KX450F for an MXA-specific bike build. Let us count the reasons.

(1) Shootout winner. The KX450F is the best bike of the bunch for 2012. It deserves such billing thanks to the explosive powerband, improved handling and technological innovations. The KX450F is, for all intents and purposes, the cream of the crop. Wiseco knows that it’s much easier to polish a gem than to turn a piece of coal into a diamond.

(2) Problem areas. As excellent as the 2012 KX450F is, there are several issues with the clutch, suspension, exhaust system, chain guide and front brake. Wiseco, with the help of several other aftermarket companies, wanted to showcase their products and potentially make a bulletproof KX450F.

(3) Popularity.
Kawasaki is riding a wave of success lately. In recent years, the green crew has won several of MXA‘s coveted shootouts. With Ryan Villopoto’s ascension to the top of the racing world in 2011, there are a lot of enthusiasts pondering an investment in a Kawasaki for their next bike purchase. 

Wiseco’s 70th anniversary KX450F?was a culmination of several aftermarket companies putting in tremendous effort to develop a bulletproof bike. Test riders were satisfied by the results.

As for the MXA wrecking crew, we were elated to stretch the throttle cable on Wiseco’s Kawasaki KX450F in celebration of the company’s 70 years in the aftermarket business. Seventy years! To commemorate Wiseco’s accomplishments, they opted for number 70 on the KX450F. Very cool.


Having a vast amount of experience with the KX450F (and a fair amount with MXA‘s tastes), the Ohio squadron knew the peccadilloes and how to address them. If Wiseco didn’t make the parts that were needed to improve the performance, they enlisted the services of other aftermarket companies. We should point out that Wiseco didn’t go overboard on the KX450F. This is a purpose-built bike that is meant to solve the few problems of an otherwise awesome machine. Don’t expect to read about works suspension, different camshafts, titanium parts or flux capacitors. Here’s a breakdown of the parts used on the Wiseco KX450F.

(1) Suspension.
The 2012 Kawasaki KX450F ranked very low in MXA‘s suspension comparison, thanks to a shock that wallows and rather soft spring rates. Wiseco knew that the suspension left a lot to be desired, which is why they hooked up with Factory Connection. Leaving no stone unturned, Factory Connection installed stiffer fork springs, changed the oil, revalved the forks and shock, and added a remote reservoir.

(2) Clutch. The clutch on the KX450F is useless. Due to the Kawasaki’s massive hit and giant powerband, the stock clutch fades quickly. Notching in the clutch-basket tangs ultimately leads to disaster. Wiseco installed a six-spring clutch, along with stiffer springs, to keep up with engine performance.

(3) Exhaust system.
Truth be told, the OEM exhaust system on the 2012 KX450F passes the sound test by sleight of hand. The tapered perf core in the mufflerquiets the bike at low rpm, but at open throttle the exhaust sounds like a scalded cat (to the tune of 122 dB). Using an aftermarket exhaust system improves sound, as well as engine output. Enter Yoshimura with their RS-4D titanium/carbon fiber exhaust. This system uses two muffler outlets.

Wiseco didn’t go overboard on the engine. They did, however, install a long-lasting clutch kit to handle the rigors of riding.
Tell us this front end doesn’t look good! Unfortunately the Factory Connection suspension was on the stiff side.

(4) Engine. You wouldn’t put a mustache on the Mona Lisa, which is why Wiseco really didn’t mess with the KX450F powerplant. Wiseco installed a higher-compression (13.5:1) piston, as well as a cam chain for reduced friction and increased service life. They also added their unique Fuel Management Controller (FMC). Designed to act like a carburetor, the FMC can adjust the air/fuel mixture for more precise tuning.

(5) Chain guide.
The KX450F eats through the chain guide and buffer pad faster than Joey Chestnut at abarbecue. Knowing the dangers of the chain wearing into the swingarm and through the chain guide, Wiseco tapped T.M. Designworks to take care of these reliability issues. T.M. Designworks installed their Baja Endurance kit, which includes a chain slider, lower roller and chain guide. These are the same parts that we’ve used on our stock KX450Fs for years.

(6) Brakes. If you have a lot of horsepower, then you had better have a lot of stopping power. The stock brakes are weak (particularly the front brake). Moto-Master contributed their oversize Flame front rotor. Thanks to a larger clamping surface, the KX450F is no longer a runaway locomotive.  Several other companies contributed to the Wiseco Kawasaki KX450F bike build. Works Connection offered up their engine plugs, Elite clutch perch, brake cap, hour meter and mount, skid plate, and oil-filler plugs. Renthal provided TwinWall 997 bend bars, a gold chain and sprockets. Twin Air contributed the filter, while CV4 took care of the high-pressure radiator cap, silicone radiator hose kit and thermal gas-tank barrier to keep the fuel from overheating. A Hammerhead rear-brake pedal (along with a large aluminum brake tip) and shift lever were used, as were Kal-Gard oils, Hann Racing sleek titanium footpegs, DeCal Works custom graphics, Bridgestone 403/404 tires, and a Guts factory gripper seat cover with traction strips.


The MXA wrecking crew was excited to test the Wiseco Kawasaki KX450F because it was an honest attempt at solving the various bugaboos on an otherwise outstanding bike. And, since Wiseco knows the way to our hearts, we were appreciative of the awesome Bridgestone 403/404 sneakers and 997 bend Renthal TwinWall handlebars (two favorites among the vast majority of testers). Obviously we felt right at home on the Wiseco KX450F. Wiseco sweetened the deal byallowing us as much time on the bike as we wanted. We’re sure that if we really pushed, we could have kept the bike forever. Greed, however, is not a virtue, and we have a steady stream of bikes waiting in the queue to be tested.

Yoshimura provided their eye-catching RS-4D exhaust system. The two-hole muffler improves bottom-end response.

The most outstanding improvement on the Wiseco KX450F was the clutch. Typically, the KX450F eats the stock clutch pack as an appetizer and moves right into the clutch basket. That’s not the case with the Wiseco clutch. Brutal as we were to the clutch, it was fade-free and consistent throughout the test. Even the worst clutch abusers couldn’t wear down the plates. The Wiseco clutch is a good buy for any year model KX450F.    

Yoshimura’s RS-4D titanium/carbon fiber exhaust system looked trick and received a lot of attention from looky-loos in the pits. Most MXA test riders prefer the single-hole muffler design, claiming that the two-hole exhaust improves low-end response but tamps down midrange and top-end power. The RS-4D beefed up the torque curve and tamed the midrange hit slightly. That’s not a bad thing, considering the KX450F powerband can be too much for less skilled riders.

We’ve had success with Wiseco’s Fuel Management Controller in the past and appreciated how easy the instrument was to use. Wiseco hid their FMC under the seat on the KX450F. By removing the seat bolts, we had instant access to the air/fuel mixture. It was a benefit at high altitudes and in colder conditions where a few minor tweaks to the system boosted engine performance. The FMC doesn’t increase the amount of horsepower, but enhances fuel delivery for a crisper-running engine. It’s a very cool accessory, especially fortechnology geeks.

Test riders were pleased to discover that the KX450F came with a stronger front brake, aftermarket exhaust and bulletproof clutch.

As mentioned previously, Factory Connection handled the suspension duties. F.C. essentially gutted the suspension and started from scratch. They do impressive work, but apparently our signals got crossed for this bike test. Why? Factory Connection set up the suspension way too stiff. Initially, we dialed back the clickers and messed with the sag, but the suspension wasn’t as forgiving as we would have liked. It took a ham-fisted rider with a general disregard for safety to get the Factory Connection suspension to work properly. We sent the forks back for a revalve.


We commend Wiseco and its cadre of aftermarket companies for taking a shot at resolving some of the troublesome issues on the 2012 Kawasaki KX450F. For the most part, they succeeded. We appreciated that Wiseco targeted specific areas without going overboard on a bike that doesn’t need a total make-over. They tried to resist tacking on useless gadgets that would only raise the curb appeal. And, we’d be lying if we said that we weren’t happy to test the bike in sunny SoCal instead of on ice in Ohio in winter. Most of all, we’d like to congratulate Wiseco on 70 years of business! For more information, visit Wiseco online at www.wiseco.com.

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