| Feature | Specification |
|---|---|
| Model Code | CG33C / 17D6 |
| Production Years | 2010-2013 |
| Engine Oil | SAE 10W-40 API SG/JASO MA (0.8 L) |
| Spark Plug | NGK CR8E |
| Front Tire | 80/100-21 51M (1.0 bar / 14.5 psi) |
| Rear Tire | 100/90-19 57M (1.0 bar / 14.5 psi) |
The 2010-2013 Yamaha YZ 250 F, specifically the CG33C/17D6 generation, holds a unique place in motocross history as the last of the high-performance 250cc four-strokes to utilize the legendary Keihin FCR-MX37 carburetor before the industry-wide shift to electronic fuel injection. Most notably, this era introduced the Bilateral Beam Frame, a sophisticated aluminum structure composed of 20 different forged, cast, and extruded sections, engineered specifically to centralize mass and optimize lateral rigidity.
Engineering Evolution: The 5-Valve ‘Genesis’ Head
While competitors were moving toward four-valve designs, Yamaha stayed true to its ‘Genesis’ 5-valve DOHC layout for this generation. This configuration allowed for a larger total intake valve area and optimized gas flow at high RPMs. The 17D6 model benefited from a revised intake port shape and lightweight titanium valves, providing a linear power delivery that remains a favorite for riders who prefer the tactile response of a mechanical throttle cable over digital mapping.
Technical Maintenance Specifications
To maintain the high-revving nature of the CG33C, strict adherence to fluid and ignition intervals is critical. The engine utilizes a semi-dry sump lubrication system. For standard operation, 0.8 liters of SAE 10W-40 meeting JASO MA standards is required. Given the lack of an oil filter in some internal paths and the high thermal load, frequent changes (every 3-5 hours of racing) are recommended by MotoSpecsLab experts.
Ignition and Chassis Setup
The ignition system relies on an NGK CR8E spark plug. Ensuring the gap is within spec is vital for preventing flame-out during technical landings. For the chassis, the CG33C is sensitive to tire pressure; both the 21-inch front and 19-inch rear tires should be set to 1.0 bar (14.5 psi) for a standard balance of traction and rim protection on intermediate terrain.
MotoSpecsLab Verdict
The 2010-2013 YZ 250 F is a masterpiece of mechanical engineering. It represents the ultimate refinement of ‘old school’ technology—carburetion and 5-valve heads—packaged in a ‘new school’ bilateral beam chassis. For the modern vintage racer or the weekend warrior, it offers a level of reliability and mechanical simplicity that modern EFI bikes struggle to match.