Honda CB TWO-FIFTY – MC26 Specs: Engine Oil, Gap & Tire PSI

While often overshadowed by its high-performance siblings, the Honda CB Two-Fifty (MC26) holds a unique engineering distinction: it utilizes a highly refined evolution of the CD250U parallel-twin engine, specifically engineered with a 360-degree crankshaft. This configuration provides a distinct exhaust note and torque delivery profile that prioritized urban longevity and thermal stability over raw peak horsepower, making it one of the most reliable commuter platforms ever manufactured by Honda.

AttributeSpecification
Production Years1991 – 2008
Engine TypeAir-cooled, 4-stroke, Parallel Twin (SOHC)
Oil SpecificationSAE 10W-40, API SJ/SL, JASO MA/MA2
Oil Capacity1.5 Liters
Front Tire90/100-18 54S (Tubeless)
Rear Tire120/90-16 63S (Tubeless)
Battery TypeYTX7L-BS
Spark PlugNGK CR6HSA (Gap: 0.6–0.7 mm)

Technical Overview

The MC26 generation represents the pinnacle of Honda’s ‘utility-first’ philosophy. The air-cooled 234cc powerplant is renowned for its simplicity, featuring a single Keihin constant velocity carburetor and a maintenance-friendly SOHC valve train. Its chassis, a steel diamond frame, provides the necessary rigidity for urban maneuvering while maintaining a low center of gravity.

Maintenance Protocols

Lubrication System

To preserve the integrity of the plain bearings and the integrated gearbox, MotoSpecsLab recommends using a high-quality semi-synthetic 10W-40 oil. Given the air-cooled nature of the MC26, ensuring the oil meets JASO MA2 standards is critical to prevent clutch slippage under high thermal loads. Total capacity is 1.5 Liters.

Tires and Contact Patch

The MC26 utilizes a specific 18-inch front and 16-inch rear wheel combination. Maintaining precise pressures is vital for handling predictability:

  • Front: 2.00 bar (29 psi)
  • Rear (Solo): 2.25 bar (33 psi)
  • Rear (Passenger): 2.80 bar (41 psi)

Ignition and Electrical

The electrical system is supported by a YTX7L-BS maintenance-free battery. For optimal combustion efficiency, the NGK CR6HSA spark plugs must be gapped strictly between 0.6 and 0.7 mm. Fouled plugs on this model often indicate a rich condition in the pilot circuit of the carburetor.

MotoSpecsLab Verdict

The Honda CB Two-Fifty (MC26) is a masterclass in mechanical restraint. It does not chase specifications; it chases 100,000-mile durability. For the technician or the dedicated owner, adhering to the 1.5L oil interval and monitoring the specific 16/18-inch tire pressures will ensure this machine remains a reliable staple of the garage for decades.

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