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Description
The Fatty Gold Series Pipe Is the Cornerstone of FMF's History. With Over 35 Years of Experience Behind It, FMF's Fatty Pipe Is the Industry Benchmark. Their Philosophy Is Simple - Give You More Power. More at the Crack of the Throttle, More in the Meaty Part of the Powerband, and More Over the Top. The Fatty Is a Symbol of FMF's Heritage and Dedication to Performance.
FEATURES
- Computer designed and dyno-tested to make power gains where each machine needs them the most
- Offer better bottom and top power
- Tru-Flo stamping process ensures a perfect fit and optimum performance
- Constructed of strong 19-gauge steel with a nickel-plated finish
Technical Specifications
- MFG. Part Number 020145
Vehicle Information
Yamaha YZ125 Dirt Bike (1974-2026)
The Yamaha YZ125, a legendary motocross racing motorcycle, has been a dominant force on tracks worldwide since its introduction in 1974, continuing its legacy through 2026. Powered by a 124cc or 125cc two-stroke single-cylinder engine, this model has consistently evolved, adapting to the demands of competitive riding. Over its extensive production run, the YZ125 has undergone several significant generational shifts. Initially air-cooled from 1974 to 1980, it transitioned to a liquid-cooled engine in 1981, marking a major performance upgrade. Further advancements included the introduction of the Yamaha Power Valve System (YPVS) in 1982 and a comprehensive overhaul in 1996 with a new chassis and engine refinements. A pivotal change occurred in 2005 with the adoption of a lightweight aluminum frame, replacing the long-standing steel unit, alongside a redesigned engine and advanced suspension. More recently, 2020 saw the debut of the YZ125X, an off-road specific trim, followed by significant engine and component revisions for both the YZ125 and YZ125X in 2022 and 2023, ensuring its continued competitiveness. FAQ:
Q: How do I know which parts fit my Yamaha YZ125?
A: To ensure perfect compatibility, please use the year and edition selector at the top of this page to specify your exact model.
Maintenance
| Component | Interval | Details |
| Engine Oil (Transmission Oil) | 5 hours (aggressive use) or 10-15 hours (recreational use) | Refers to transmission oil. Capacity of approximately 0.66 L for some models. Use 10W-30/10W-40 motorcycle transmission oil. |
| Oil Filter | During every transmission oil change (if present) | YZ125 models typically do not have a traditional engine oil filter. A screen or strainer may be present for the transmission oil. |
| Spark Plug | Inspect regularly, replace as needed | Critical wear item for two-stroke engines. Check for fouling and wear. Gap and type may vary by year. |
| Air Filter | 2-5 hours (aggressive use) or 5-15 hours (recreational use) | Intervals vary significantly by model year and dust conditions. Frequent maintenance is essential. |
| Coolant | Check before every ride; change every 6 months (racing) or annually (regular) | Applicable to liquid-cooled models (from 1981 onwards). Change or check every 40-50 hours. Capacity of approximately 0.93 L for recent models. Use ethylene glycol-based coolant. |