The KFX®400 is for serious sport riders who demand high-performance for the track, trails and dunes. And the KFX400 delivers, thanks to its high-tech, four-stroke engine, manual transmission, lightweight racing-type chassis and disc brakes.

  • 2006 Kawasaki KFX 400
  • Year:
  • Make:
  • Model:
  • Horsepower @ RPM:
  • Displacement:
    398 L
  • Price:

This four-wheeled Kawasaki is propelled by a highly responsive 398cc, liquid-cooled, four-stroke engine with double overhead cams and four valves atop a chrome composite-plated aluminum alloy cylinder. Fed by a 37mm high-performance carburetor, it includes electric start and has a counterbalancer to reduce vibration.

The KFX400 engine utilizes a “dry sump” design, shortening overall engine height so it can be placed lower in the chassis for enhanced stability while providing higher ground clearance.

Transmitting power from the engine to the rear wheels is a high-performance five-speed-plus-reverse manual transmission and efficient O-ring chain.

2006 Kawasaki KFX 400
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Such power requires a chassis to match, so the KFX400 ATV engine rides in a high-tensile steel frame and subframe. Suspension duties are handled by dual front A-arms with fully adjustable shocks that provide 8.5 inches of travel, while an aluminum-alloy swingarm with fully adjustable shock provides 9.1 inches of travel on the rear. Contributing to the KFX400’s low, 373-pound dry weight are competition-inspired aluminum-alloy wheels, and stopping power is provided by dual front disc brakes and a single rear disc brake.

Kawasaki KFX 400 Specifications

  • Engine: Liquid-cooled, four-stroke, single cylinder with DOHC and four-valves
  • Displacement: 398cc
  • Carburetion: Mikuni BSR37
  • Starting: Electric
  • Transmission: Five-speed-plus-reverse manual, multi-plate wet clutch
  • Final drive: #520 O-ring chain
  • Frame type: High-tensile tubular steel alloy
  • Front suspension / wheel travel: Dual A-arms with coil-over-shock, adjustable preload / 8.3 in.
  • Rear suspension / wheel travel: Swingarm with preload-adjustable shock / 9.1 in.
  • Front tires: 22x7-10 radial
  • Rear tires: 20x10-9 radial
  • Front brakes / rear brake: Dual hydraulic discus / Disc
  • Overall length: 72.0 in.
  • Overall width: 45.9 in.
  • Wheelbase: 49.0 in.
  • Ground clearance: 10.4 in.
  • Lighting: Dual 30W halogen
  • Dry weight: 373 lbs.
  • Fuel capacity: 2.6 gal.
  • Footpegs: Serrated steel
  • Colors: Kawasaki Lime Green, Blazing Orange


  • High-performance four-stroke engine delivers exceptionally broad torque curve for maximum traction for a variety of sport-riding conditions
  • Twin air intakes on the front fenders provide extra cooling to the radiator
  • Dry-sump lubrication allows the engine to be kept low in the chassis for superior weight distribution and handling while providing higher ground clearance
  • 37mm carburetor increases engine performance
  • Electric start makes getting started easy
  • Five-speed manual transmission helps the rider keep the engine in the powerband
  • Reverse gear makes backing up convenient and easy
  • Efficient chain final drive provides maximum power to the rear wheel
  • Swingarm utilizes eccentric chain adjusters, making chain adjustment easier
  • Dual A-arm front suspension and rear swingarm help to soak up the bumps and jumps
  • Front shocks feature fully adjustable compression and rebound damping as well as adjustable preload for multiple suspension tuning options
  • Triple disc brakes provide exceptional stopping power
  • Dual halogen headlights brighten the path for nighttime riding
  • Serrated steel footpegs help to keep the rider’s feet from slipping in wet or muddy riding conditions 
Cyril Demortier
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  (1) posted on 04.23.2015

This is for you guys having a gas flow problem on your KFX 400. You say it does not run when pet is in on position. It seems to run out of gas, yet runs fine when pet is in "prime" position. Here’s the problem. The vacuum hose from carburetor to the pet is either not connected, or cracked or broken. The other fix is to purchase a pet for a Raptor (I won’t mention the brand) it installs very easy,(same dimensions) in your KFX & then simply plug the vacuum port on the carb. I found the same problem when I got my 2004 in 2011. Replaced vacuum hose, problem solved! Piece of Cake Mate!

  (1) posted on 02.24.2012

Great bike, owned mine (a 2003 model) for about 3 years now. When both are in stock form, it will beat a 400EX in a drag race. But unless all you do is straight lines, they are pretty much equal. The one thing that makes this machine stand out on a long ride is the T-shaped seat. It is by far the most comfy seat on any sport quad I have driven. Honestly, if you want a comfier ride than what the KFX400 offers when you aren’t tearing up a trail like a madman, you will have to look at a Polaris Sportsman model. The seat is that good!

Compared to the rest of the sport market like the 450’s and larger, the handling is right on par with the rest of them, if not better than some of them. The only few that I can think of that it is better for general handling aspects is the Raptor 660’s (Raptor 700’s are improved over the 660 making it on par with the KFX400), DS650’s, KFX700’s, and the Predator/Outlaw line. The main reason for this is all of these machines are quite heavy for a sport quad, but they do have much more power than the KFX400 to back it up in the open spaces. Only the Polaris machines will have a hard time reeling the KFX400 back in when in the open ground where it can put down its power. The same goes for the 450’s, but since they are among the same weight as the KFX400, their high strung 450 powerplants can almost always overcome the 400 given that the rider’s abilities are equal.

I am not saying the KFX400 is slow, but the acceleration to its top speed just takes longer than a typical 450. For those of you who just HAVE to know the "top speed" of the KFX400, I have logged a top speed so far of 69mph with aftermarket exhaust and air filter with a modified airbox lid on the stock sprockets.

The greatest trait of this bike is that it is cheap to own. When you compare prices to the 450’s, it is considerably cheaper to buy! The only thing you are missing out on is the power of a 450, but everything else is there as it handles just as well as any 450 (Doug Gust proved this a while back with a DOMINATING race season back in what I think was 2004 or 2005.). However, the KFX has a far better seat, so its a good tradeoff in my opinion as I doubt there is more than 20% of KFX400 owners/future owners who will use the machine for competition racing. Also, as a plus, parts are fairly cheap including the aftermarket. That is, so long as you search a few websites for the best deals. Ebay is usually a good bet.

As for reliability, mine has been great to me for the last 3 years. I am not a hard and aggressive rider, but my KFX400 hasn’t been given an easy time by me either. I am in the middle somewhere. The machine hasn’t needed any major work with no parts pre-maturely breaking or wearing out fast.

So all things considered, this is probably one of the most cost-effective machines out there for the everyday rider who likes to have fun on any level.

  (1) posted on 07.15.2011

i have a kfx 400 and it has a white brothers slip on a 410 kit and jetted charb it runs about 70-75 mph i race it with built 450s and beat em u dont have to have alot of bike for a track you have to have skill

  (1) posted on 02.6.2010

i own a 2004 kfx400. its tough to keep it running if u ride it to the limits but it had lots of pick up even with stock sprockets. ive reccomended it to many people. i have also absolutely smoked a 400ex, its got the speed even when geared down, shortly after i rolled mine, my handle bars snapped off whick is kinda a pain in the if you 50 kms away from anything so if u roll it, get the bars changed or your gonna have problems later, i also have to agree with the motor burning oil an the timing chaing having to be adjusted but overall its a great machine with lots of power and speed, she’ll do anything u want her to as long as u have the money to fix it later

  (6021) posted on 03.25.2008

this thing id recomend any thing before it!!!!!!!!!

  (6021) posted on 03.17.2008

this bike is so great that if u want a quad u shold get it...... its got speed power and every thing else get it

  (6021) posted on 03.17.2008

this bike is so crappy i can beat it on my 300ex the kfx is so great i would recommond it to evey body in the world

  (6021) posted on 03.16.2008

i want to buy a 2004 kfx 400 but i wanna know is it fast if it is how fast can it go i wanna know and if it haves problems like does break fast or runs out of gas fast help plz ???????

  (6021) posted on 03.16.2008

i want yo buy one but is it fast and those is it break fast???? help plz

  (6021) posted on 03.8.2008

I own the ltz 400 which is that same exact motor and frame. I really have beat the kfx 450 but i have a yoshi pipe and k&n filter. the only reason i beat the 450 was he had too much power for the loose gravel and just spun before taking off in second gear.

  (1) posted on 06.26.2007

I just got a KFX400 and I have the same problems with my gas valve in ON position, it would just die after I get lower then 1/2 tank.

It doesn’t seem to want to go back into NEUTRAL after riding it for a period of time. You have to go to 2nd then down or turn it off then on to putt it in N.

Anyone else have this problems?

  (1) posted on 01.28.2007

Yea I just bought a 2006 KFX 400 and when I have the gas tap in the "on" position the bike will run for a while and then cut off. However, if I ride in the "prime" position the bike runs like a champ. Can anyone help me with this problem?

  (1) posted on 01.20.2007

i have a 06 kfx400 and i love it to death. but last weekend at the drag strip i came into contact with a non racer that felt the need to cross the drag strip. i now have a kfx400 with i bent frame. i have a neighbor with a 03 kfx400 with a blown engine. will the 03 frame work with the rest of my 06 setup????

  (6021) posted on 11.20.2006

i own a ltz 400 and one thing you need to know about the ltz/kfx/dvx is you will need to change the timing chain yearly if you ride it alot mine recently blown up for sum unknown reason that was not a factory problem and if u have problems like this you can replace the top end with an athena top end for 550$ wick is much cheaper than oem i also had to replace my crank so i bought a hot rods crank that saved me like 200 over oem you will love the bike it only has the thing with the timing chain to wory about and carefull tighting your oil tank drain plug

  (6021) posted on 11.5.2006

man i own a yfz 450 and my friend has an 06 kfx400 and i own him in a race i mean by more then enough mine is quite a bit faster. the only race a kfx stock could beat a stock yfz is in reverse and only because yfz do not have reverse

  (6021) posted on 11.4.2006

yeah i have a 2006 kfx400 and i love the thing i has so much power i can hardly belive it i had a 2001 400ex before but thats a childs toy after ridinf the kfx i would recommend this bike to anyone who is looking to buy one it is really fast to i got her doing 139 kph the other day and i compelety blew past my buddy who was on his 2004 raptor660 liked he was tied onso who ever who want to buy one do so really good bike to ride.

  (6021) posted on 10.24.2006

I just recently bought my 2006 kfx about a month ago and i have nothin bad to say about it my buddies all like honda’s and they didnt like my bike when i first got it then i raced my buddy with 400ex with an fmf pipe,carb,air filter.. and i absolutelyblew past him by 5 or 6 quad lenths .. the bike is really good in trails,water,mud.sand, anything it handles liek a dream and gives the best ride.. wheelies.. they come up like nothin even 2nd and 3rd gear .. i recomend this bike to anyone who is lookin to buy a 400 its alright for beginers east to ride and its awsome for intermidiate .. i take it on the track is has no problem keepin up with 660’s they only beat me buy a little bit... deff a good investment ...... good job kawasaki!!!

  (6021) posted on 10.19.2006

i have a kfx 400 with a 440 kit and about another 2,500 in to the motor it is really fast i went 83 mph on it the other day down a paved road with my friend on the back it can high 90 mph with just me on it but i also have a rev limiter so if i didnt have that i could go even faster prolly another 5 mph i lov my quad it is so awsome and it handles well in the air

  (6021) posted on 10.5.2006

I have a 04 orange one, sooped up. Its pretty fast. They go around 69 to 73 mph depending on the bike setup. I like mine and i can get wheelies in every gear and ride them for ever. But its a lie if you say it can beat a 450, maybe if it was bored out.

  (6021) posted on 09.4.2006

My 06 kfx 400 is a sweet bike, it handles any trail out there but I can’t seem to keep it running. This will be its second trip to the shop in 2 months. It dies when I slow down from high speeds, leaks oil, and it seems to burn oil when running. I would suggest an extended warrantee when you buy it, and compared to the trx 450 it stands it’s ground.
Maybe i got a lemon

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