Make Model



2003 - 04


Four stroke, single cylinder, SOHC, 4 valves per cylinder


510.4 cc / 31.1 in
Bore x Stroke 95 x 72 mm
Cooling System Liquid cooled


Keihin MX FCR 39


CDI Kokusan 4K-3


Electric & kick


5 Speed

Final Drive


Front Suspension

43mm WP USD fork

Front Wheel Travel

295 mm / 11.6 in

Rear Suspension

Fully adjustable WP

Rear Wheel Travel

320 mm / 12.6 in

Front Brakes

Single 260 mm disc

Rear Brakes

Single 220 mm disc

Front Tyre

90/90 - 21

Rear Tyre

140/80 - 18
Wheelbase 1481 mm / 58.3 in
Seat Height 925 mm / 36.4 in

Dry Weight

112 kg / 247 lbs

Fuel Capacity

8.5 L / 2.2 US gal / 1.9 Imp gal



It comes as no surprise the EXC is well suited for woods duty. The precise-shifting, wide-ratio 6-speed transmission and liquid-cooled 4-valve OHC motor work in harmony to create a formidable package. It has a low enough first gear that it can easily conquer the steepest hill climbs or a complicated single-track at a mellow pace. Dial in an upshift or two along with some liberal wringing of the throttle you can have quite the e-ticket ride up that same trail. The electric start makes recovering from failed attempts much easier than if it was kick-start only. It does come with a kick-starter, though, just in case.

Even with its 58.3-inch wheelbase, the 525EXC feels extraordinarily nimble for an open classer. At 265 lbs. full of fuel, it’s obvious KTM did a great job of distributing the weight because it feels lighter than it is. Our resident photo-hound and official WORCS photographer Tyler Maddox was particularly impressed with the 525s disposition in the woods.

“I can’t believe how light it feels on the trails,” explained Maddox, owner of an enduro-spec KTM 125SX. “The only time I really noticed the weight was when it carried that extra inertia through the high-speed turns. I was surprised how slim it was, too.”

Low rpm power delivery from the 510cc motor is one of the bike’s positive attributes. It feels even more potent than the dyno results reveal. The long-stroke Single (95 x 72mm bore and stroke) and 11:1 compression ratio combine to produce a substantial 34 lb.-ft. of torque at 6000 rpm. Horsepower on our test unit topped out at a respectable 44.4 hp at 7600 rpm. Usable power arrives down low and signs-off sooner than track-tuned motors like the 450SX, but it is the linear power curve that makes the 525EXC so versatile. The motor revs quick and pulls really hard yet never seems harsh.

During one of our first forays into the woods, one of our test riders tried to wheelie over a large log that had fallen across the path. Unfortunately, while in the middle of the maneuver, he just slammed into it and smashed the right underside of the frame in the process. A skid-plate is one of the necessary aftermarket items we definitely recommend. The chrome-moly steel chassis features a double-cradle design and a removable aluminum subframe.

Thanks to its tall gearing and meaty motor, the 525 is just at home in the desert as it is in the woods. Our guide in the Idaho desert, test-rider Tony Severa, recommended we head to Reynolds Creek, a popular riding area that begins at Hemmingway Butte OHV Park located south of Nampa. Severa, who owns a 2003 KTM400SX, was particularly impressed with the big orange monster.

“This bike is incredible,” Severa said so eloquently after returning from his first ride. “I love that extra power and it feels so small and similar to my bike. I want one.”

With the higher speeds attainable in the desert came the opportunity to really tax the fully adjustable suspension. The 48mm WP inverted fork is splendid. It only bottomed out on the biggest of hits (according to our air-certified colleagues) and almost always kept the front wheel tracking in the right direction. The linkageless WP shock that attaches to a long swingarm is equally up to the task, once properly adjusted. As delivered, it had a tendency to buck the rider in the braking bumps and rough trails at high speed. Once plugged in with more rebound damping the rear end tracked bumps much better.

Together this set-up provides a generous 15.2 inches of ground clearance and a civilized 36.5 inch seat height. We did experience some headshake a couple times in the desert portion of the test, but that often comes with the territory when you ricochet the front wheel off a rock at 70 mph.

New bright orange bodywork features angular lines that mix with the titanium-colored frame to give the 525EXC a distinctive, factory appearance. The plastic holds up fairly well against abuse but it becomes scruffy once scratched up. In particular, the lower portion of the tank where boots make consistent contact looks hammered on our tester. The graphics are tough, they’ve managed to survive attacks from various plant life, sedimentary rock and the occasional fuel spill yet they still look good peeking out from under a thick layer of mud after a hard ride. The one-piece tail and side number plates are great for quick tear downs, but the area for placing numbers is pretty small.

Prospective owners will be tempted by an impressive array of quality hardware on the 525EXC. Tapered, oversized Magura bars and an aluminum kickstand are standard equipment, as are wide, titanium-looking footpegs and quality Excel wheels. The 21-inch front hoop holds a 90/90-21 tire while the rear utilizes a 140/80-18-spec tire.

Top-shelf brakes feature steel-braided lines, a two-piston Brembo caliper gripping a 260mm wave rotor on the front, while a single-piston Brembo clamps to a 220mm wave rotor in the rear. The braking components are powerful, provide excellent feedback and never ever faded or howled in complaint. The firm gripper seat is decent at first, but its edges can cause some butt chafing after several hours of riding. Unfortunately, its 2.25-gallon tank never seems to run dry, so quitting because you’re out of gas won’t be a viable excuse.

One tool a serious enduro rider needs is a multi-function instrument panel, and here the KTM delivers in spades. The clean LED display, accessible by way of a 3-button pad on the left-side handlebar, has all the functions you could ever want. In addition to a typical speedometer and hourmeter, there are also two average-speed displays, two tripmeters, and a place to enter wheel-size calibration codes if you decide to change the hoops for supermoto duty. Nice.

The sharp-handling 525 has become a favorite among our testing crew during the two months of abuse we’ve thrown at it. It goes anywhere you point it, the electric start makes life easier if you are having an off day, and a nice hydraulic clutch makes maneuvers in the tight stuff that much easier.

Review by: Ken Hutchinson, Motorcycle-USA