FMF Factory Fatty (Works) Top 7 Reasons Why This should Be Your Choice

FMF Factory Fatty (Works) Top 7 Reasons Why This should Be Your Choice

The FMF Factory Fatty: A Performance Powerhouse for Motocross

The FMF Factory Fatty is more than just a throwback to the days of handmade Works pipes—it's a high-performance piece of equipment designed to give your motocross bike a significant boost. Made using lighter gauge steel, the Factory Fatty broadens and smoothes out the power curve, resulting in gains throughout the power band, including more low-end, more mid, and increased over-rev (FMF Racing).

A Handmade Powerhouse

The Factory Fatty is not coated, leaving the bare metal exposed. This allows the heat-affected weld areas to turn colors, enhancing the “Works” look. Each pipe is formed and welded by hand, using 19-gauge steel for the head pipe section and 20-gauge steel for the rest of the pipe body.

Performance Booster

The use of lighter gauge steel in the Factory Fatty allows it to gain better low-to-mid power and higher over-rev compared to standard pipes using heavier gauge steel ( The powerband from the Factory Fatty is much smoother, making power delivery easier to manage.

Comparison to Other Pipes

When compared to other pipes, the Factory Fatty stands out. For instance, the FMF Gnarly pipe, made with thicker 18-gauge steel, offers better bottom-end power and a quicker transition into the midrange. However, the Factory Fatty the body of the pipe is constructed from 20 gauge steel, which is on the lighter side. The header portion, on the other hand, employs a slightly thicker 19 gauge steel. The power curve becomes more expansive and smoother, with a significant enhancement in performance across the entire power band. This includes an increase in low-end and mid-range power, as well as an improved over-rev performance.

Keeping it Clean

Maintenance of the FMF Factory Fatty does require a bit more effort. Since the pipe is not coated, it can rust if not properly cared for. However, after washing the bike, ensure the pipe is thoroughly dry. Any emerging rust spots can be treated with WD-40 and a Scotch Brite pad. While it might require a bit more elbow grease, the increased power and the “Works” look make it worth the effort.

Top 7 Reasons:

  1. Better power in low and mid ranges with Higher Over-Rev
  2. Smooth power band, predictable
  3. Lightweight 20 gauge steel body
  4. Tougher 19 gauge steel header
  5. Bare Metal Finish (Works Finish)
  6. Hand welded and pounded seams
  7. Made 100% in the USA

Available for 65cc, 85cc, 125cc and 250cc

Click Here To see all the Factory Fatty Pipes

Note: Comes in a raw, unplated, oiled finish, must be oiled after washing - looks great in raw steel 

Available for - Honda, Yamaha, Kawasaki, Suzuki, KTM, Husqvarna, and Gas Gas 


If you're a motocross enthusiast looking to give your bike a significant performance boost, the FMF Factory Fatty is worth a look. With its hand-formed and welded design, improved power delivery, and signature “Works” look, the Factory Fatty is a top choice for many riders. Yes, it might require a bit more maintenance, but the benefits far outweigh this minor inconvenience. After all, who wouldn't want more power throughout the entire powerband? Make the choice, go with the FMF Factory Fatty.

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