1978 Harley-Davidson MX-250
Engine: Aermacchi 242.6 cc (0.2 L) Two-Stroke One-Cylinder
Cooling System: Air-Cooling
Ports: Five
Power: 32.41 HP at 9,000 RPM
Torque: 18.91 lb-ft at 9,000 RPM
Compression Ratio: 11.8:1
Carburetor: Dell’Orto PHB E 38
Venturi Diameter: 38 mm
Main/Pilot/Starting Jets: 155/70/75
Throttle Valve: 40
Jet Needle: K2
Needle Jet: 26C AB
Air Screw Setting: 1.5 turns
Air Filter: Polyurethane Foam Element
Bore: 72.0 mm
Stroke: 59.6 mm
Lubrication System: Fuel and Oil Mixture 20:1
Starter System: Primary Kick
Ignition: CDI Dansi/CDI Motoplat
Ignition Timing: 0.100 in. (2.5 mm or 21°) before Top Dead Center
Trigger Air Cap: (Dansi) 0.012-0.016 in.
Spark Plug: Champion N59G
Spark Plug Electrode Gap: 0.020 in. (0.5 mm)
Battery: None
Transmission: 5-Speed Manual
Clutch: Wet, Multi-Plate
Primary Drive Pinion/Crown Wheel Gear: 22 teeth/60 teeth
Primary Reduction: 2.73
Gear Ratio: 1 - 14/28, 2 - 18/28, 3 - 21/26, 4 - 21/21, 5 - 23/19
Shift Pattern: One Down, Four Up
Gearbox Sprocket: 14 teeth
Chain Type: Regina HP 5/8 by 3/8
Weight: 253 lbs.
Length: 83.6 in.
Handlebar Width: 34.2 in.
Ground Clearance: 12.0 in.
Wheelbase: 57.3 in.
Seating Capacity: One Driver
Seat Height: 34.2 in.
Steering Angle: 45° Left and Right
Steering Head Angle: 30°
Trail: 5.5 in.
Body Material: Plastic
Fender Maker: NAVA/Preston Petty
Frame: Double Downtube
Suspension Manufacturer: KYB
Front Suspension: Telescopic, Oil-Dampened with 9 in. of Travel
Rear Suspension: Swinging Arm, Oil-Dampened with 6 in. of Shock Travel and 9 in. of Wheel Travel
Fuel Tank Capacity: 2.2 gallons
Transmission Fluid: 1.0 quart
Front Forks: 36 mm Diameter, 210 cc Capacity
Original Tire Manufacturer: Cheng Shin
Front Wheel Tire: 3.00 by 21
Rear Wheel Tire: 4.40 by 18
Brakes: Drums, Internal Expanding, Single Leading Shoe Type, 140 mm by 25 mm
Rims: Akront, Shoulderless Light Alloy
Spokes: 36 per Wheel, 4 mm Diameter
Hub Manufacturer: Leleu
Tire Pressure (front and rear): 10 PSI
VIN Number: 7DxxxxxH8
Rarity: One of Approximately 1,000 MX-250’s
Comments
Harley davidson made something different than 2 wheeled boats?
Yes. In the 1970’s, there was a craving for dirt bikes that Harley-Davidson wished to satisfy following its acquisition of Italy-based Aermacchi in the 1960’s. These earlier bikes didn’t do so well against their Japanese competition, being more expensive, more heavy, and less powerful than them. In 1975, a prototype MX-250 was made; determined to be the start of a major entry in motocross, around sixty of them were built with the blessing of its parent company, American Machine and Foundry. These were odd because for their rear suspension, they used a modified set of front forks. With 1977’s arrival, the MX-250 got further revised into its current specification; made from this year to 1978, in both years, only a thousand production models were released. In this state, it was able to take several podiums. Despite this success, AMF-Harley-Davidson would shut down the program after the 1978 season, selling Aermacchi to the Castiglioni brothers. In their hands, the motocross operation would be branded Cagiva, which won the 1985 125 World Motocross Title.
HD made minibikes too lmao
ThatElementGuy (Element Squad), ThatWeirdGinger (Mr. E36), Seth (BlogSquadOwner) (pizza), and just a random dude, here it is!
Found on kijiji?
NICE
Thank you!
I have no Idea why I got notified for this post but your bike is realy nice 👌
Thank you!
Thats pretty sweet
Thank you!
But can it do a BURNOUT?
On tarmac or on the dirt?
9000 RPM
Yes; after that, the power and torque drop off pretty quickly!
Owned a Harley before it was cool!
I have yet to get on it and take it for a spin. From what I’ve read, they can be a bit fussy with their handling and that one has to know how to use that power band along with its relatively heavier weight. With that being said, I’m excited to have such a rare artifact of motocross history!
Those details tho! Nice!!!!
Thank you!
Wow. Those details lol.
Thank you! When I was first searching for it, I found virtually no information on it. I then dug a bit more, and there was a site that had almost all of these specifications on it!