ProX Steel Exhaust Valve 09260148 for Yamaha WR400F 1998–2000 YZ400F 1998–1999 YZ426F 2000–2002

Name: ProX Steel Exhaust Valve 09260148 for Yamaha WR400F 1998–2000 YZ400F 1998–1999 YZ426F 2000–2002
Brand: PROX
SKU: 09260148
Price: 22.42 GBP
Availability: InStock

Fits 3 bikes

RRP £28.02 Save 20%

£22.42

incl. VAT

In stock — delivered in 6–10 working days

Dispatched in 2–3 working days · delivered in 6–10.

Part #: 09260148

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§ 02 / About this part

What it is

ProX steel exhaust valve to fit Yamaha WR400F (1998–2000); Yamaha YZ400F (1998–1999); Yamaha YZ426F (2000–2002).

Positioned in the cylinder head, this valve manages the flow of combustion gases. It is a direct replacement for OEM part 5BE-12121-00. Over time, heat cycles and high RPM cause the face to cup or the stem to stretch. Replacing worn valves is critical during a top-end rebuild to maintain compression. Check your valve seats for wear before installation. New seals are essential when fitting this part to your bike. It offers a durable alternative to titanium for riders prioritising longevity in harsh enduro or MX conditions.

§ 03 / Specs

The numbers

Brand: PROX
Part number: 09260148
Category: Top End
Weight: 0.04 kg
OEM cross-refs: 5BE-12121-00
VAT: 20%

// Fitment

Will it fit your bike?

Fits 3 models · 3 year-bands

Yamaha 3 models

* Fitment data is provided as a guide. Verify compatibility against the bike's owner's manual or service handbook before ordering. Iron Offroad accepts no liability for incorrect application. Full terms and conditions apply.

§ 05 / About Iron Offroad

Iron Offroad

Iron Offroad is the off-road sibling of Iron City and Iron Stable — a UK shop for motocross, enduro, and trail-bike hard parts. Every fitment lives on the site, listed against KTM, Husqvarna, GasGas, Yamaha, Honda, Kawasaki, Suzuki, and Beta. Pick your bike on the timing-tower. Our USP is the data: fully enriched fitment so you find the right part for your bike quickly and get it fitted accurately. Brands you'd find on a paddock workbench — pads, sprockets, plastics, fork seals, cables, gaskets, bars, the things that actually wear out. Road-bike kit, scooter parts, and quad gear sit elsewhere; dirt and e-moto only. We operate from our storage facility in Leeds. Iron Offroad is a trading name of Iron Stable Ltd, registered in Mildenhall — Company No. 17061294. The business has a rich motorcycle history across multiple moto brands — the photos show where we came from — and recently pivoted into hard parts and online retail.