WHAT IS THE BEST TRIPLE CLAMP OFFSET?
Most MXA test riders are universal in their endorsement of 22mm triple clamps on their KX-Fs. Why? Because Kawasaki’s geometry has a tendency to tuck and push. Pulling the stock 23.5mm offset back (24.5 on 2006-07 models) increases trail, which helps the front tire track more accurately through the center-out. You will need to slide the forks up in the clamps to get the most out of the 22mm offset clamps.
CAN YOU FIX THE KX450F WITH A SHOCK LINKAGE?
Off the showroom floor, the KX450F’s rear suspension wallows and needs more compression damping. MXA’s best fix is to run a Pro Circuit linkage (it ramps up the rising rate, stiffens the initial part of the stroke and lowers the height). www.procircuit.com
HOW TO TURN THE FIVE-SPEED INTO A FOUR-SPEED?
Kawasaki’s five-speed gearbox is really the old 2006 four-speed tranny. No matter how you cut it, first gear and fifth gear are problems. Every test rider wanted the bike geared lower so that second gear would come into play sooner, third gear would be closer to second, and fifth would be more usable. Add one or two teeth to the rear sprocket. A side benefit of gearing the bike down is that you lessen the number of shifts and encourage short shifting—which reduces the number of missed shifts on the KX450F’s faulty gearbox.
WHAT IS THE QUICK FIX FOR ENGINE OVER-HEATING?
We boiled the KX450F’s water at every long or hot race we went to. We sought advice from Kawasaki mechanics, and they said to switch the 1.3 kg/cm2 radiator cap for a 1.8 (that's what the team runs). The Kawasaki part number is 49085-1077. A 1.8 kg/cm2 equals 25.6 psi. The stock 1.3 cap is 18.5 psi. A radiator cap will not raise or lower your engine's temperature, but it does raise the boiling point by three degrees per pound of pressure.
LOOKING FOR A LONG-LASTING CHAIN GUIDE?
We ate through the stock KX450F chain guide in no time (especially after we lowered the gearing). The best KX450F chain guide is the all-plastic Slide-N-Glide unit (you will need the chain buffer pad also). It lasts forever. Go to www.tmdesignworks.com for more info.
WHAT HONDA PART FITS ON A KX450F?
We hate the cotter key in the KX450F rear axle nut. Our solution? We trot down to the Honda dealership and get a stock, self-locking CRF450 axle nut.
HOW CAN YOU SET THE PRELOAD?
No bike makes it harder to get to the shock preload ring than the KX450F. The Enzo Technica preload ring allows you to get rid of the top locking ring and tighten the preload ring without having to mess with the top ring. Very trick. www.enzoracing.com
IS THIS THE WORST FRONT TIRE IN HISTORY?
The stock Kawasaki front tire is a Dunlop D742F. Kawasaki must have gone to the vintage museum to spec this less-than-spectacular front tire. This isn't even the newer D742FA, but the old disgraced 742F. This bike begs for a new front tire.
WHAT ARE MXA’S BEST STOCK FORK SETTINGS?
For hardcore racing, we recommend this KX450F fork setup:
Spring rate: 0.47 kg/mm
Oil height: 340cc
Compression: 18 clicks out
Rebound: Ten clicks out
Fork leg height: 5mm up
Notes: We turned the compression clicker all the way out for average riders (many riders would benefit from lowering the fork oil height by 5mm to make the forks more supple over small bumps).
WHAT ARE MXA’S BEST STOCK SHOCK SETTINGS?
For hardcore racing, we recommend this KX450F shock setup:
Spring rate: 5.5 kg/mm
Race sag: 100mm
High-compression: One turn out
Low-compression: Eight clicks out
Rebound: Eight clicks out
Notes: The Pro Circuit linkage drops the rear down 12mm, which kicks the head angle out. We compensate for this by sliding the forks up 2.5mm more to bring the steering back to optimum again.
Kawasaki Motorcycle test