| Component | Specification |
|---|---|
| Engine Code | MF09E (Liquid-cooled 4-stroke SOHC) |
| Displacement | 249cc |
| Oil Capacity | 1.1 L (SAE 10W-30 API SG / JASO MB) |
| Front Tire | 110/90-12 64L (1.75 bar / 25 psi) |
| Rear Tire | 130/70-12 62L (2.00 bar / 29 psi) |
| Spark Plug | NGK DPR7EA-9 / DENSO X22EPR-U9 |
| Battery | YTZ12S (12V Maintenance Free) |
Developed by Honda’s legendary “N Project”—a skunkworks team dedicated to creating lifestyle-oriented machines like the Zoomer and Ape—the PS 250 Big Ruckus represents a radical departure from traditional scooter design. Unlike its contemporaries, the MF09 eschews aerodynamic fairings for a rugged, industrial exoskeleton, featuring a sliding seat that transforms from a pillion perch to a rider backrest, a design feat rarely seen in mid-capacity utility vehicles.
Engineering Overview: The MF09 Platform
The Honda PS 250 Big Ruckus is built around a heavy-duty steel tube frame, designed to provide the rigidity of a motorcycle with the step-through convenience of a scooter. Powered by a 249cc liquid-cooled single-cylinder engine, the MF09 produces smooth, linear power delivered via a V-Matic continuously variable transmission (CVT). Its low center of gravity and 29-inch seat height make it exceptionally stable for urban commuting and light cargo hauling.
Maintenance & Service Specifications
For the professional technician or the dedicated owner, maintaining the MF09 requires adherence to specific fluid and electrical standards to ensure the longevity of the SOHC powerplant.
Lubrication System
The engine requires 1.1 liters of high-quality 4-stroke oil. Honda specifies SAE 10W-30 with an API service classification of SG or higher. Crucially, as the MF09 utilizes a dry CVT system, JASO MB oil is recommended for optimal fuel efficiency and reduced internal friction compared to JASO MA oils.
Chassis and Tires
The Big Ruckus utilizes a staggered wheel setup for a balance between agility and load-bearing capacity. The front 110/90-12 tire should be maintained at 1.75 bar (25 psi), while the wider 130/70-12 rear tire requires 2.00 bar (29 psi). Regular inspection of the tire pressure is vital, as the MF09’s weight distribution is heavily biased toward the rear when cargo racks are utilized.
Electrical & Ignition
The ignition system relies on a specific heat range spark plug: the NGK DPR7EA-9 or DENSO X22EPR-U9. The gap should be checked periodically to ensure efficient combustion. Power is managed by a YTZ12S battery, which provides the high cold-cranking amps (CCA) necessary for the 250cc starter motor.
Expert Verdict
The Honda PS 250 Big Ruckus remains a cult classic because it prioritizes function over form. From a technical standpoint, its simplicity is its greatest strength. With a robust cooling system and a proven engine architecture shared with the Reflex/Forza series, the MF09 is an exceptionally reliable machine when serviced according to the parameters outlined in this guide.
Frequently Asked Questions
While Honda suggests longer intervals, MotoSpecsLab recommends an oil change every 2,500 to 3,000 miles (4,000–5,000 km) to maintain the integrity of the 249cc single-cylinder engine.
Can I use JASO MA oil?
Yes, JASO MA is safe, but JASO MB is preferred for scooters without wet clutches, like the PS 250, to maximize efficiency.