KTM 420 (1979 to 1980)

The KTM 420 is a legendary "Big Bore" powerhouse from the air-cooled 2-stroke era, specifically representing the pinnacle of KTM’s open-class dominance in the late 1970s and early 1980s. Replacing the older 400 series in 1979, the 420 (Type 560) engine was a clean-sheet redesign that became the foundation for KTM’s most feared desert and motocross racers. The standout models, the 420 MC (Motocross) and 420 GS (Enduro), were famous for producing a brutal 56 hp while maintaining a surprisingly light dry weight of around 108 kg. This displacement eventually paved the way for the monstrous 495, but the 420 remains the favorite among vintage enthusiasts for its slightly more "manageable" power delivery and its iconic role in the transition to the Pro-Lever rear suspension and WP (White Power) forks in the early '80s.