Harley-Davidson MX 250 COMPETITION 1978 Owner's Manual

Harley-Davidson MX 250 COMPETITION 1978 Motorcycle manual cover
Pages 30
Year 1978
Language(s)
English en

Harley-Davidson MX 250 COMPETITION 1978 Motorcycle Specification

The Harley-Davidson MX 250 Competition 1978 is a vintage motocross motorcycle renowned for its robust performance and classic design. This bike features an air-cooled, single-cylinder, two-stroke engine with a displacement of 242 cc, delivering a power output that was competitive for its era. The engine is paired with a 5-speed manual transmission, allowing riders to effectively harness the power across various terrains.

The MX 250's frame is constructed from high-strength steel, providing durability and stability essential for off-road racing. The suspension system includes telescopic front forks and dual rear shock absorbers, designed to absorb impacts and maintain control on rugged tracks. The motorcycle is equipped with drum brakes on both the front and rear wheels, ensuring reliable stopping power.

Weighing approximately 99 kg (218 lbs), the MX 250 is relatively light, enhancing its agility and maneuverability during competition. The bike's ergonomics are tailored for motocross, featuring a high-ground clearance and a well-padded seat to support the rider during intense races.

Aesthetically, the Harley-Davidson MX 250 Competition 1978 embodies the classic motocross style of the late 1970s, with its streamlined design and distinctive Harley-Davidson branding. This motorcycle remains a cherished piece among vintage motocross enthusiasts and collectors, symbolizing a unique blend of Harley-Davidson's craftsmanship and competitive spirit in the motocross world.

Harley-Davidson MX 250 COMPETITION 1978 Motorcycle F.A.Q.

What type of oil should I use for the Harley-Davidson MX 250 Competition 1978?

Use high-quality two-stroke motorcycle oil that is specifically designed for off-road engines to ensure optimal performance and protection.

How often should I clean the air filter on my MX 250 Competition?

Clean the air filter after every race or every 10 hours of riding in dusty conditions to maintain engine performance and longevity.

What is the recommended spark plug for the 1978 MX 250 Competition?

The recommended spark plug is an NGK B8ES, gapped to 0.6 mm to ensure proper ignition and engine performance.

How can I troubleshoot starting issues with my Harley-Davidson MX 250?

Check the spark plug for fouling, ensure there is fuel reaching the carburetor, and verify that the ignition system is functioning properly.

What is the correct tire pressure for the MX 250 Competition 1978?

Maintain a tire pressure of 12 psi for the front tire and 14 psi for the rear tire for optimal traction and handling.

How do I adjust the chain tension on my MX 250 Competition?

To adjust chain tension, ensure there is about 1 inch of slack in the chain at the midpoint between the sprockets. Adjust using the rear axle adjusters if necessary.

What are the signs of a worn-out clutch on the MX 250 Competition?

Signs of a worn-out clutch include slipping under load, difficulty engaging gears, and a noticeable change in the clutch lever feel.

How do I perform basic maintenance on the suspension of the MX 250?

Regularly check for leaks around the fork seals, ensure proper fork oil level, and inspect suspension components for wear and damage.

What should I do if my Harley-Davidson MX 250 is overheating?

Ensure the radiator fins are clean, check coolant levels if applicable, and verify that the carburetor is not running too lean.

How can I improve the performance of my MX 250 Competition 1978?

Regular maintenance, such as keeping the air filter clean, using high-quality oil, and proper carburetor tuning, can help improve performance. Consider upgrading the exhaust system for additional power gains.