2006–2007 · Enduro · Buyer's Guide
57 Horses In 249 Pounds
This 300 EXC is a two-stroke enduro built around usable drive rather than peak numbers. The liquid-cooled 293 cc single makes 57 hp and 28 lb-ft, and the spread matters more than either figure. It pulls cleanly from low revs, lugs a tall gear through rock and roots without constant clutch work, then still revs out eagerly when the trail opens up. The chassis has the same focus: a steel double-cradle frame, a fully adjustable WP 1.9-in (48 mm) upside-down fork and PDS shock, and 15.2 in (385 mm) of ground clearance. There are no rider aids at all. Everything happens between your right wrist and the rear tire.
It was one of the lightest full-size enduro bikes of its era, and that low weight is what keeps you fresh deep into a hard day. It ages honestly, but it needs hands-on care. The Keihin PWK36 carb wants rejetting when altitude or temperature swing, the power valve needs periodic decarboning, and the stator, clutch plates, fork seals and plastics all wear under hard use. The good news is that the work is simple and the aftermarket is deep. This is a bike for experienced off-road riders who don't mind turning a wrench. If you want to ride for years without touching a tool, look elsewhere.
Spec sheets don't ride bikes, but they set the baseline.
| Power | 57 hp (42 kW) |
|---|---|
| Torque | 28 lb-ft (38 Nm) |
| Displacement | 293 cc |
| Engine | Single-cylinder |
| Cooling | Liquid-cooled |
| Gearbox | 5-speed |
| Final drive | Chain |
| Fork | Upside-down (USD) |
| Front tire | 90/90-21 |
| Rear tire | 140/80-18 |
| Wheelbase | 58.1 in (1475 mm) |
| Ground clearance | 15.2 in (385 mm) |
| Front travel | 11.8 in (300 mm) |
| Rear travel | 13.2 in (335 mm) |
| Seat height | 36.4 in (925 mm) |
| Fuel capacity | 2.2 gal (8.5 L) |
Equipment check
Chassis
Ignition system failures
Some owners report intermittent loss of spark or difficult starting, often traced to a failing stator or wiring issues. Replacing the stator is the typical fix.
Clutch slippage under high load
The multi-plate clutch can begin slipping, especially under hard acceleration or when the oil is old. Replacing worn plates restores full engagement.
Brake fade during prolonged use
Under sustained heavy braking, the stock brake pads may overheat and fade, reducing stopping power. Upgraded pads and fresh fluid mitigate this.
Fork seals prone to leaking
Fork seals can leak oil after extended use, especially if the chrome tubes are nicked or dirt gets past the wipers. Regular inspection and cleaning help prolong seal life.
Power valve sticking from carbon buildup
The power valve mechanism can become gummed up with carbon deposits, causing inconsistent power delivery and poor throttle response. Regular cleaning resolves the issue.
Carburetor jetting sensitive to conditions
The Keihin PWK36 carb can be finicky to jet correctly; symptoms include hard starting, bogging, or rich running. Periodic adjustment is needed when altitude/temperature change significantly.
Cracked plastics and loose hardware
Vibrations and frequent falls can crack body panels and cause bolts to loosen. Regularly checking fasteners and replacing damaged plastics is required.
Where this KTM 300 EXC pulls ahead of — or falls behind — its rivals on the numbers, and the typical bike in its class on character.
Power
Torque
Displacement
Seat height
Forget spec-sheet bragging. Here's who the 300 EXC is actually built for.
This is squarely your bike. It's light, torquey and fully adjustable, so it climbs ledges and crawls sand washes all day. Just plan on rejetting the carb when altitude or temperature swing hard.
Made for Bar M / Kane Creek · Imperial Sand Dunes · Johnson Valley OHV Area
It handles a closed course far better than you'd expect, but the broad, torquey power is built for trail traction. It's great for practice days. A dedicated motocrosser still belongs on the gate.
Made for Carnegie State Vehicular Recreation Area · Fox Raceway at Pala · Glen Helen Raceway
Only if you travel very light. It will cross the gnarliest BDR sections with ease, but a 2.2 gal (8.5 L) tank, a tall seat and no luggage system make multi-day logistics a real puzzle.
Made for AZBDR — Arizona Backcountry Discovery Route · California BDR South · COBDR — Colorado Backcountry Discovery Route
If this one isn't quite the fit, these are the bikes worth riding back-to-back against it.
