It's utterly amazing that a company could be this honest. Better than honest: blunt to the point of saying this just might be too much bike for you!

BASIC FACTS ABOUT THE RACING FOUR STROKES

KTM is offering two basic engine sizes for 2000; the 400 and the 520. The SX version is for MX and Supercross racing, while the electric-start EXC models are designed for enduro and/or cross country racing.

FRAME

As far as its basic structure is concerned, the main frame of the SX and EXC Racing models precisely corresponds to the frame geometry of the KTM 2-stroke models. Only the split cradle down tube sections, which were adapted to the 4-stroke engine, and a few retaining brackets, were slightly modified. The sub-frame is made of aluminum and fixed to the main frame by means of a screw connection. FORK

The 2000 Racing models are equipped with the new 43 mm WP USD (Up Side Down) fork, which is a multi-adjuster fork, which means that both the compression damping and the rebound damping can each be separately adjusted on either fork tube, thus offering an enormously large regulating range. The WP USD 43 fork is very light and has different internal settings for the SX and the EXC models, respectively. The forged fork leg axle clamp is lightweight and offers maximum ground clearance. A newly designed 180 degree fork protector gives good protection to the USD tubes.

PDS SHOCK

The WP PDS Shock 2000 is specifically racing-adjusted for both the SX and the EXC design.

HANDLEBAR MOUNTING SYSTEM

The top triple clamp is forged with an undamped, variable position, handlebar clamp system. The handlebar clamps can be attached in two optional positions to the triple clamp (i.e. front and back position). Additionally, the handlebar clamp itself, with a diameter of 28 mm, has an eccentric bore, giving you six different handlebar positions. The tapered handlebar is a new Magura Aluminium item.

FOOTPEGS Footpegs of the SX models are 10 mm longer to reduce the danger of slipping and ensure that the rider is supported squarely, especially on landings from high and long jumps.

SWINGARM

These Racing models have a new swing-arm with a rounded profile and new axle passage. The chain adjusting mechanism can be rotated 180 degrees to allow rapid changing of final drive sprockets. Milled marks allow precise chain adjustment and exact rear wheel alignment.

BRAKES

The rear brake cylinder of the Racing models has a smaller piston diameter (12 mm), which gives the rider a significantly better opportunity to apply the precise amount of brake pressure required. Front brake levers of the SX models are provided with a spring preload feature, which not only allows exact adjustment of the lever position, but also keeps the lever precisely in the selected position.

A new design front wheel brake caliper and caliper support will not flex and in combination with the new Toshiba brake linings (which have 10 % more braking power), the best possible brake performance is realized.

Special shaped brake disks include features that limit the accumulation of dirt to a minimum. A cambered outer radius ensures that dirt particles, which tend to accumulate above the slots, are removed. Wedge-shaped slots, which protrude beyond the path of the linings, cause the dirt particles to drift off toward the inside. The brake discs are mounted directly at the hubs. Those of the EXC models have the magnet directly integrated.

HUBS/FRONT AXLE

The new bikes have lightweight and nickel-plated front and rear hubs. The front hub is equipped with a larger 20 mm front axle (previously it was 17 mm) that is required by the 43mm WP fork. The new axle increases frontal rigidity and adds stability allowing the front fork to work at its optimum.

SPOKES

New, lightweight 4.5mm double-tapered spokes are in the front wheel, and extra strong 5mm spokes are laced in the rear. Spokes are chrome-plated for corrosion resistance, and should continue the reputation of strength and durability KTM wheels are famous for.

MAIN SILENCER

SX and EXC silencers are the same as far as diameter and length are concerned. However, their interior components are different and adapted to the respective requirements.

LOOKS

Racing models SX and EXC are designed to match the look of the 2-stroke sport models. The basic color combination is orange/silver. The design of the 2000 models is familiar from the Motocross World Championships: highly fashionable retro design in silver/black. A matching non-skid seat cover is available on SX models. SX models are additionally provided with white number plate backgrounds.

SIDESTANDS

EXC Racing models are equipped with aluminum side stands. No stands are on the SX bikes.

TIRES

SX and EXC Racing models all come with Bridgestone tires.

RIMS

SX bikes come with Excel (19" Rear) and EXC bikes are equipped with D.I.D. (18" rear).

ENGINE

KTM Racing models are equipped with a totally new engine, with new centercases, new transmission, new head, new cylinder, new side covers; everything is new! The kickstarter is located on the right side of the engine.

The original starting point of development, the Husaberg engine, has virtually disappeared. The clutch is the only component that has not been changed. All other components were developed by KTM and are totally innovative:

Weight difference between the SX and the EXC model is approximately 8 kg. The total weight of the 520 EXC (ready to ride, but without gasoline) is approximately 115 kg/246.8 lbs (dry weight approx. 112 kg), the total weight of the 520 SX (ready for operation) is approximately 107 kg/235.9 lbs.

CENTERCASES

Sand-cast aluminum centercases are considerably stronger (up to 20 % more) than die-cast cases. The surface of the bottom of the cases is flat (like a skidplate) thus largely preventing the engine from catching on uneven terrain. For optimal heat dissipation, the centercases have no surface coating.

The new 4stroke Racing engine is narrower than the current KTM 2-stroke engines. Sprocket alignment is the same as in KTM 250cc 2-stroke models, but the transmission cases are 12 mm narrower on the right side (clutch side). The ignition cover and the clutch cover are made of lightweight magnesium and powder coated.

TRANSMISSION

Transmission components are not mass-produced, but cold-sunk, which is an extremely accurate forging technique that ensures top quality and durability with minimal machining. The SX version has 4 speeds, and the EXC version has 6 gears. Conversion is relatively easy and requires only 2 gear wheels.

ELECTRIC STARTER

The SX version is equipped with a kickstarter, while the EXC version has an additional electric starter. The electric starter is located directly behind the cylinder and engages on the primary gear side. It's a lightweight system and the starter engine weighs only 0.88 kg. By comparison, the small electric starter of the LC4 weighs 1 .2 kg, and the Husaberg starter an even 2 kg. Therefore, an extremely light 4 Amp battery can be used. This battery is mounted in the air filter box.

In addition to the automatic decompression (all models), the bikes also feature a hand decompression lever.

ENGINE LUBRICATION

All of the new Racing models are equipped with 2 oil pumps. The first oil pump draws oil from the gearbox and is filtered via two paper filters. Oil is then pumped simultaneously to the camshaft (also lubricating the top end) and to the crankshaft. The second oil pump returns oil from the crankcase to the transmission system.

All oil lines - but one - are integrated into the centercase. There is a total of 7 integrated lines. Integrated oil lines are less likely to be damaged and significantly reduce the overall weight. An oil level viewer replaces the oil dipstick. A microfilter is integrated into the centercases.

The new Racing engine is unique in its central, low-weight ventilation system, which works via the balancer shaft. A centrifugal oil interceptor prevents oil from leaking out of the engine through the ventilation openings.

INSIDE THE ENGINES

The 520 engine is equipped with a forged piston. Components are top quality: precision-forged rocker arms, nitration-hardened valves, progressively wound valve springs on a two-spring system basis, aluminum spring retainers with special valve guide seals as well as case-hardened adjusting screws. The timing chain is narrow, divided and riveted.

The cylinder, in contrast to the LC4, mounts in unison with the cylinder head to the centercases, which means a weight reduction of more than 1 kg for the cylinder alone. Crankshaft design uses needle bearings for the conrod and a silver-plated cage, as well as roller bearings. All of these new four stroke Racing engines are equipped with a balancer shaft.

IGNITION SYSTEM

Racing models are equipped with a digital Kokusan ignition system. The SX version weighs 0.4 kg less than the EXC version. Flywheel diameter is 80 mm in 400 SX models and 106 mm in 520 SX and 400/520 EXC models.

CARBURETOR

The Racing carburetor is a Keihin with a throttle position sensor. In combination with the digital ignition system, information on both the current r.p.m. and throttle position is transmitted to the ignition box. The ignition curve is optimized for every load condition, which improves engine response and reliability.

COOLING

Racing models have a high capacity water pump integrated into the cylinder head. The head flow pattern is guided around both the intake and the exhaust port channels.

CLUTCH

Racing models have no separate outer clutch hub. The function of the outer clutch hub is performed by the clutch gear. Therefore, the clutch is extremely narrow, using thin clutch discs.

OIL MAINTENANCE

Each of the two oil pumps is additionally protected by an oil screen of its own. These screens can be removed from outside and easily cleaned. They are sealed with reusable O-rings. The oil pressure relief valve is integrated and accessible from outside.

Don't even think about buying a 520 SX for a fun or play bike! This is not an easy bike to ride. It has snappy, sudden power - and lots of it - combined with an ultra-sharp steering chassis.

This means that things happen RIGHT NOW! No doubt, in the hands of a good Pro rider, this machine would be a great deal of fun. However, in the hands of a crusty old fat guy who used to be semi-quick, the KTM 520 SX is intimidating.

The bike feels light, slim, trim and tall. It's set up to turn sharply, with a near vertical 26.5 degrees fork rake angle. For a tight, twisty supercross track, it'll probably turn with (or under) anything else on the course. But on a normal outdoor MX track with higher speeds, the 520 SX becomes a hand full, demanding total attention to keep from getting pitched off.

It's only fair to say that the bike moves around a great deal in the process of going forward. As long as I anticipated the bumps, or hit them squarely, I was able to cope with the speeds the bike was capable of generating. But when I got tired and tried to ride lazy to save energy, the bike seemed to get a mind of its own and deflect way too easily for my limited reflexes.

To be utterly honest, this particular bike deserved some laps in the hands of a good Pro to truly evaluate its capabilities. Therefore, the stuff you read here is tainted from my own abilities, or lack thereof.

Power starts early and hard in the 520, with much more snap off the bottom than a YZ-400/426. Mid-range is positively brutal ... even stronger than the bigger 650 XR Honda. The bike also revs out well. The spread of power is so wide, that the four-speed tranny is not a handicap for a normal MX or Supercross track.

Engine response is clean, with no hitch or stumbling anywhere. Much of the response can be credited to the carb that's mapped to the variable curve ignition system.

KTM told us that swapping the four-speed box, for a six-speed set up, is simple. Just remove a clip and add the needed pieces. Shifting was excellent. It had the kind of touch and feel where you never even thought about shifting as you rode the bike, which is how it should be.

The hydraulic clutch was smooth and light, but there was so much power available at all times, that you really never had to use it except for starting and shifting. And, if you choose to abuse the gearbox a bit, you can slam it into the next gear without using the clutch.

I felt that the suspension was too firm - almost harsh - but the way the bike is delivered, means that it has to be able to take the landing from one of those ball-busting launcher double jumps. Naturally, you'll be able to dial in compression and rebound at both ends to suit your style, bodyweight and skill level (or lack of) easily.

The 520 SX (as well as all the other bikes in the family) is very thin through the midsection, with nothing to snag boots, or get in the way of the rider. I'm 5 feet 8 1/2 inches short, and found the tall saddle height irritating. Much of this height stems from the fact that the bike has 15 inches of ground clearance.

For some reason, the saddle on all four of the bikes we tested was very hard, much like the seats of the KTMs from a decade ago.

Little things on the bike are great! Take the grips, for instance. Up until now, I've always thought the Honda grips (properly trimmed with a razor blade) were the best in the world. The Domino grips on the Katoom are just like the Honda grips already trimmed in the critical palm and thumb area.

Bars are tapered aluminum items that would cost you a bundle to add to your garden variety race bike. Like we said, nice stuff. And certainly one of the six available bar positions will fit your body just about right.

Attention to detail is so good that someone returning to the sport after a decade away, might think it was a show bike. The exhaust system is chrome-plated, aluminum parts are buffed out, nuts and bolts are high-quality pieces, welds are clean and even the graphics show a bit of classic restraint in an era of pop-art flash bikes.

Oh yes ... let's jabber a bit about starting. Most four-strokes are a real pain in the a ... uhhhh ... ankle. When the very first KTM four stroke was introduced to the market as a 504 powered by a Rotax engine, it was easy to start.

But when KTM brought out their own engine and dumped the Rotax, they acquired a reputation for hard starting that was certainly deserved. Those bikes had a mind of their own and would sometimes refuse to start, unless you bowed toward Mecca, lit three candles, said a rosary and burned some incense.

The new generation racing four-strokes put all this behind, as they start without mystery, and start consistently.

The bottom line?

If you want a true, pure-blooded, four stroke racer, this is it. Like we said, in less than stellar hands, it is not an easy bike to ride aggressively. Power is all you could ask for and more than most riders will ever need. In fact, the legendary "average" rider will probably go faster with less fatigue on ordinary, less powerful bikes. It's a deadly serious machine and you better think long and hard before you get one. If your skill level isn't high enough, having a KTM 520 SX would be much using an Indy car to make a beer run down to the local 7-11.

Which brings us to the ...

There is a weight difference, with the SX hitting the scales at 235.8 pounds ready to ride, less fuel, while the EXC tapes in a 246.8 pounds. But THE BIG DIFFERENCE is the electric starter! You got it, amigo. The EXC starts just by tickling a little button mount on the right side bar. It burbles to life immediately, and settles down to a comfortable idle.

What makes the 520 EXC so amazing, is that it weighs about 30 pounds less than the Honda XR650R, and it has that electric foot. What a bonus!

Now for the best news. For a number of minor reasons, the EXC is worlds easier to ride than the hard-core SX racer. Because the ignition of the EXC has heavier lighting coils (almost a pound difference in weight), the engine doesn't hit with quite the violent burst of the SX. Also, there's a spark arrestor (USFS approved) on the pipe that mellows the power out a bit more.

We're told that the valving is slightly softer on the forks and shock than the SX model, which translates into a more plush ride, and actually slows down the quick handling to an acceptable level for those with less than National level riding skills.

Even this fat, grumpy old rider loved the EXC! There's no doubt in my mind that I was able to turn much faster lap times on the slightly heavier and mellower EXC, than with the brutish SX. Please don't think that the EXC is a slug. Far from it. Run hard through the gears, and the front end torques off the ground unless you pay attention.

On twisty fire roads, riding the EXC is almost like cheating. You can charge deep into a turn, tap the powerful brakes to set the bike up, and hang the rear end out to dry, just like those flat track guys.

Would this make a good Baja bike? Yes, of course. Except, like we noted up front, the EXC is a very serious race bike and will require more regular maintenance than, let's say, an XR Honda.

Still, all things considered, the 520 EXC is the best all-around production four-stroke race bike it's been my pleasure to ride.

This is the MX and/or Supercross version of the mid-sized pure racing four-stroke. Much like the 520 SX, the 400 SX was ultra-quick steering and demanded attention when pushing it even at the 90 percent level.

Speed? It seemed to have a lot more low rpm power than the YZ-400, and at least as much mid-range, but the Yamaha revved higher and longer. It weighs the same as the 520 SX, at 235.8 pounds ready to ride, but with no gas in the tank. It's lighter by a few pounds than the Yamaha and feels much lighter than the 520, even though the scales tell you the truth.

Equipped with a four-speed gearbox like the 520 SX, it's clear that the 400 is also designed for close-course racing. There's no way you're going to gear a close-ratio fours-speeder up for cross country or GP racing. However, like the 520, the 400 will accept a six-speed box, if needed.

I stalled the 400 a few times when landing from a jump because my foot was forced down on the brake pedal from the G-force. If it was my personal bike, I'd find some way to "soften up" that rear brake a bit.

As with the 520 SX, the 400 seemed on the stiff side, suspension-wise. Since the entire quartet of four-strokes shares the same chassis, forks, shock, swingarm, etc., you would think they would all handle the same.

Not so. Each bike had a distinct personality.

For some reason, I did not like the Bridgestone M77/M78 tires that came with the bikes, and genuinely disliked the 19 inch rear wheel on the SX models. On the fun fireroads, those 19 inch rear tires simply did not hook up and the rear end spent a lot of time slithering around, rather than driving the bike forward.

Oddly, the 18 inch tire on the EXC models offered acceptable traction when compared t the 19 incher.

Much like the difference between the 520 SX and EXC, then400 EXC offers a much more user-friendly ride than the MX version. Again, you're dealing with a slightly heavier ignition, a six-speed wide ratio gearbox and a woods-legal spark arrestor on the exhaust. As with the 520 EXC, the 400 EXC uses the 18 inch rear wheel, instead of the SX-oriented 19-incher.

While the 400 EXC is a very serious cross-country/enduro/hare scrambles race bike, it's also one that could be ridden comfortably by that legendary "average rider" we were talking about earlier.

Power delivery is plenty strong - certainly stronger than the WR 400 Yamaha - but it is a fairly easy bike to ride. Mid-range power is especially impressive, and if you keep the bike singing in the fat part of the range, there's not much around that's going to pull you through the gears.

Again, because of the shared components, the 400 EXC weighs exactly the same as the 520 model.

Like the 520 EXC, the 400 has the oh-so-sweet electric starter. You'll find the smallish battery in the air box under the saddle. KTM told us that it was good for about 25 five-second cranks before it needed some running time to re-charge it.

While we're peering at the battery in the air box, you'll find an easily removable big air filter in there. It seems to be well protected from the elements.

Maintenance on all four of the bikes is identical. You'll find four filters in the lubrication system. Two of them are replaceable items and the other two are cleanable screens. Only one oil line of the seven is not built in to the center cases, which saves weight and eliminates oil leaks. There's an oil level viewer to check the level, rather than a conventional dipstick. Only 1250 ccs of oil is required, and frequent oil changes are recommended for longer engine life.

After riding all of the bikes, we are duty bound to tell you to think about the EXC models first, unless you plan to do some very heavy-duty MX or SX racing. The SX models are powerful, light, sophisticated machines not designed for those with limited skills.

Of sure, they're fun to ride and will give you a thrill that's hard to match. But if you think you want to buy a 520 SX to go out and have fun with your trail riding pals, it won't take you very long to realize the bike is over-kill and your buddies will probably beat you on their three year-old bikes, as you fight to keep the 520 SX from spitting you off the back.

It's a brute, pure and simple. In the right hands, it can win a GP in stock trim. In the wrong hands, you're going to wish you had put that deposit down on that XR Honda instead. If you consider the 520 EXC, you'll more than likely fall in love with the bike. While considerably more user-friendly than the 520 SX, it's still a very powerful bike that has the ability to open your eyes wider than nature intended.

And yes, there is that electric starter, old friend.

On the list of "Bikes I Want," the 400 SX is last in this group of four. Why? Not because it's bad in any way, it's just that it's as twitchy and nervous as the violent 520 SX, but doesn't deliver the same cheap thrills.

I figure as long as you're going to scare yourself, you might as well scare yourself halfway nuts.

It would be hard to go wrong with the 400 EXC for an all-around race/off-road bike. You could enter an enduro with this bike, and race a local MX just by removing the nicely tucked-in sidestand and putting the headlight/number plate on the workbench.

Still, when you think four stroke, it's hard to argue against a big-inch thumper. Therefore, all things considered, I would lay my personal money down for the 520 EXC and immediately get my forearms into some serious condition so I could learn to hang onto this thing.

The real bottom line is that KTM has just re-written the rulebook on the future of four strokes.

Engine; Single Cyl. 4-Stroke, SOHC/4 Valve Head, Liquid Cooled, Automatic Decompression System
Cylinder; Mahle Nikasil Coated
Exhaust; Twin Head Pipe, Two Into One Collector
Silencer; Aluminum Muffler
Bore/Stroke; 95.0mm X 72.0mm
Displacement; 5l0ccm
Trans; 4 Speed, SX Close Ratio
Gear Ratios; 1st -14:34, 2nd - 17:31, 3rd - 19:28, 4th - 22:26
Primary Drive; 30:81
Final Drive; 14 / 50, 520 chain
Trans Oil; SAE 10W-40 wt.; Capacity 1200cc
Spark Plug; NGK CR8 EK
Fuel; Premium Fuel (92+Octane U.S. Octane)
Fuel Capacity; 7.5L/2.0 U.S. gallons
Carb; Keihin MX-FCR 39
Jetting; Main: 1 75 Idle: 48 Start: 85 Needle: OBDTM Slide: #1 5 Needle Position: #2 Mixture Screw: 1½ Turns Out
Ignition; Kokusan 4K3 Electronic, w/ Lighting Coil 12 v 110w
Timing; 5 degrees B.T.D.C. @ 1000 R.P.M.
Frame Type; Mainframe: Chrome-Moly
Subframe; Aluminum
Fork; WP 43 USD, MA
Fork Travel; 295mm/11.6 inches
Fork Oil; SAE 5 wt.
Rake Angle; 26.5°
Front Brake; 260 mm/10.2" Disc, Brembo Double Piston Caliper, Sintered Pads
Front Tire; Bridgestone M77 80/100 X 21"
Shock; WP PDS, External Adjust Compression/Rebound
Rear Wheel Travel; 320mm/12.6 inches
Rear Brake; 220mm/8.65" Disc, Brembo Single Piston Caliper, Organic Pads
Rear Tire; Bridgestone M78 11 0/90 X 1 9"
Seat Height; 92 5mm/36.4 inches
Wheelbase; 1481 mm/57.3 inches
Ground Clearance; 380mm/15.0 inches
Weight; 107kg/235.8 lbs. (dry)

Engine Type; Single Cyl. 4-Stroke, SOHC/4 Valve Head, Liquid Cooled, Automatic Decompression System
Cylinder; Mahle Nikasil Coated
Exhaust; Twin Head Pipe, Two Into One Collector
Silencer; Aluminum Muffler w/ Krizman USFS Approved Spark Arrestor
Bore and Stroke; 95.0mm X 72.0mm
Displacement; 5l0ccm
Transmission; 6 Speed E/XC, Wide Ratio
Gear Ratios; 1st - 14:34, 2nd - 17:31, 3rd - 19:28, 4th - 22:26, 5th - 24:23, 6th - 26:21
Primary Drive; 30:8 1
Final Drive; 14/50, 520 O-Ring Chain
Trans Oil; SAE 10W-40 wt.; Capacity 1200cc
Spark Plug; NGK CR8 EK
Fuel Type; Premium Fuel (92+Octane U.S. Octane)
Fuel Capacity; 9L/ 2.4 U.S. gallons
Carb; Keihin MX-FCR 39
Jetting; Main; 1 75 Idle: 48 Start: 85 Needle: OBDTM Slide: #1 5 Needle Position: #2 Mixture Screw: 1 ½ Turns Out
Ignition; Kokusan 4K3 Electronic, w/ Lighting Coil 12v1 10w
Ignition timing; 5° B.T.D.C. @ 1000 R.P.M.
Frame; Mainframe: Chrome-Moly
Sub Frame; Aluminum
Fork; WP 43 USD, MA
Fork Travel; 295mm/11.6 inches
Fork Oil; SAE 5wt .
Rake Angle; 26.5°
Front Brake; 260 mm/10.2" Disc, Brembo Double Piston Caliper, Sintered Pads
Front Tire; Bridgestone M77 80/100 X 21"
Shock; WP PDS, External Adjust Compression/Rebound
Rear Wheel Travel; 320mm/12.6 inches
Rear Brake; 220mm/8.65" Disc, Brembo Single Piston Caliper, Organic Pads
Rear Tire; Bridgestone M78 110/100 X 1 8"
Seat Height; 92.5mm/36.4 inches
Wheelbase; 1481 mm/57.3 inches -
Ground Clearance; 380mm/15.0 inches

Engine Type; Single Cyl. 4-Stroke, SOHC/4 Valve Head, Liquid Cooled, Automatic Decompression System
Cylinder; Mahle Nikasil Coated
Exhaust; Twin Head Pipe, Two Into One Collector
Silencer; Aluminum Muffler
Bore and Stroke; 89.0mm X 64.0mm
Displacement; 398ccm
Trans; 4 Speed, SX Close Ratio
Gear Ratios; 1st - 14:34, 2nd - 17:31, 3rd - 19:28, 4th - 22:
Primary Drive; 30:81
Final Drive; 14 /50, 520 chain
Trans Oil; SAE 10W-40 wt.; Capacity 1200cc
Spark Plug; NGKCR8EK
Fuel; Premium Fuel (92+Octane U.S. Octane)
Fuel Capacity; 7.SL/2.0 U.S. gallons
Carb; Keihin MX-FCR 39
Jetting; Main: 175 Idle: 48 Start: 85 Needle: OBDTM Slide: #1 5 Needle Position: #2 Mixture Screw: 1 ½ Turns Out
Ignition; Kokusan 4K3 Electronic, w/ Lighting Coil 12v 10w
Ignition Timing; 5° B.T.D.C. @ 1000 R.P.M.
Mainframe; Chrome-Moly
Sub Frame; Aluminum
Fork; WP 43 USD, MA
Fork Travel; 295mm/11.6 inches
Fork Oil; SAE 5 wt.
Rake Angle; 26.5°
Front Brake; 260 mm/10.2" Disc, Brembo Double Piston Caliper, Sintered Pads
Front Tire; Bridgestone M77 80/100 X 21"
Shock; WP PDS, External Adjust Compression/Rebound
Rear Wheel Travel; 320mm/12.6 inches
Rear Brake; 220mm/8.65" Disc, Brembo Single Piston Caliper, Organic Pads
Rear Tire; Bridgestone M78 11 0/90 X 1 9"
Seat Height; 92.5mm/36.4 inches
Wheelbase; 1481 mm/57.3 inches
Ground Clearance; 380mm/15.0 inches
Weight; 107kg/235.8 lbs. (dry)

Engine Type; Single Cyl. 4-Stroke, SOHC/4 Valve Head, Liquid Cooled, Automatic Decompression System
Cylinder; Mahle Nikasil Coated
Exhaust; Twin Head Pipe, Two Into One Collector
Silencer; Aluminum Muffler w/ Krizman USFS Approved Spark Arrestor
Bore and Stroke; 89.0mm X 64.0mm
Displacement; 398ccm
Trans; 6 Speed EXC, Wide Ratio
Gear Ratios; 1st -14:34, 2nd - 17:31, 3rd - 19:28, 4th -22:26, 5th - 24:23, 6th - 26:21
Primary Ratio; 30:81
Final Drive; 14 /50, 520 O-Ring Chain
Trans Oil; SAE 10W-40 wt.; Capacity 1200cc
Spark Plug; NGKCR8EK
Fuel; Premium Fuel (92+Octane U.S. Octane)
Fuel Capacity; 9L/2.4 U.S. gallons
Carb; Keihin MX-FCR 39
Jetting; Main: 1 75 Idle: 48 Start: 85 Needle: OBDTM Slide: #1 5 Needle Position: #2 Mixture Screw: 1½ Turns Out Kokusan 4K3 Electronic, w/ Lighting Coil 12v1 10w
Ignition Timing; 5° B.T.D.C. @ 1000 R.P.M.
Mainframe: Chrome-Moly
Sub Frame; Aluminum
Fork; WP 43 USD, MA
Fork Travel; 295mm/11.6 inches
Fork Oil; SAE 5 wt.
Rake Angle; 26.5°
Front Brake; 260 mm/10.2" Disc, Brembo Double Piston Caliper, Sintered Pad
Front Tire; Bridgestone M77 80/100 X 21"
Shock; WP PDS, External Adjust Compression/Rebound
Rear Wheel Travel; 320mm/12.6 inches
Rear Braake; 220mm/8.65" Disc, Brembo Single Piston Caliper, Organic Pads
Rear Tire; Bridgestone M78 110/100 X 18"
Seat Height; 92.5mm/36.4 inches
Wheelbase; 1481 mm/57.3 inches
Ground Clearance; 380mm/15.0 inches
Weight; 112kg/246.8lbs. (dry)