Upgrade the power delivery of your 1997 or 1998 Yamaha YZ250 with the FMF Fatty expansion chamber pipe. Designed for an all-around increase throughout the power range, this FMF pipe helps deliver stronger, more usable performance across the engine’s operating band while maintaining the responsive character expected from a motocross two-stroke.
The FMF Fatty pipe features an electro-nickel-plated finish designed to resist chipping and discoloration during normal riding conditions. Its construction is engineered for off-road and motocross use, providing a durable replacement for the original expansion chamber. The Fatty configuration is intended for riders seeking balanced performance rather than a powerband focused exclusively on low-end torque or peak top-end output.
Fitment: This FMF expansion chamber fits the 1997 Yamaha YZ250 and 1998 Yamaha YZ250. Verify the motorcycle model and year before installation to ensure proper compatibility. Brand: FMF. Manufacturer part number: 020149. Vendor part number: 78-1378.
Features:
- Power Delivery: Provides an all-around power increase throughout the Yamaha YZ250 power range.
- Pipe Style: Fatty expansion chamber configuration for balanced performance across low, mid, and upper RPM operation.
- Finish: Electro-nickel-plated surface helps provide a non-chip finish that resists discoloration.
- Construction: Built for motocross and off-road riding applications with durable expansion chamber construction.
- Fitment: Fits 1997 Yamaha YZ250 and 1998 Yamaha YZ250 models.
- Brand: FMF.
- Manufacturer Part Number: 020149.
- Vendor Part Number: 78-1378.
Fitment:
1997 Yamaha YZ250
1998 Yamaha YZ250