Engine Valve Pair for Yamaha YFM350 / YFM400 series. This aftermarket valve set provides high-quality intake and exhaust valves designed as direct replacements for Yamaha ATV engines. Sold as a matched pair to ensure balanced performance and consistent seal under demanding off-road conditions. Built to withstand heat and vibration, these valves offer reliable operation across the Yamaha YFM350 Bruin/Grizzly and YFM400 Kodiak/Big Bear model families.

Vehicle Fitment

 

Product Specifications

 

OEM Cross-Reference Information

OEM cross-reference numbers are provided for reference purposes only. Always verify fitment using your machine's exact model, year, and original part number before ordering.

Why Choose This Aftermarket Valve Pair?

• Broad Vehicle Coverage: Compatible with a wide range of Yamaha YFM350 and YFM400 models including Warrior (1987–2004), Raptor (2004–2013), Grizzly (2007–2014), Bruin (2004–2006), Wolverine (1995–2009), Big Bear (1987–2012), and Kodiak (1993–2006) .

• OEM Cross-Reference: Cross-references genuine Yamaha part numbers 1UY-12111-01-00 (intake) and 1UY-12121-01-00 (exhaust) .

• Premium Aftermarket Support: Industry leaders like ProX and Wiseco manufacture compatible valves for these engines .

• Precision Manufacturing: Valves are manufactured of premium grade steel to exact OEM specifications and tolerances .

• Proven Compatibility: Confirmed fitment across multiple Yamaha 350cc and 400cc engine variants with extensive aftermarket validation .

• Demanding Conditions: Built to withstand heat and vibration, offering reliable operation across the Yamaha ATV family.

• Restores Performance: New valves improve compression, combustion efficiency, and overall engine output.

Installation Notes:

• Always check valve-to-guide clearance during installation.

• Inspect valve seats and recut or replace if necessary.

• Use new valve seals and springs where recommended.

• Properly lap valves to ensure a gas-tight seal.

• Verify valve stem clearance falls within factory specifications.

• Follow manufacturer torque specifications for assembly.

Why Upgrade?
Worn or burnt valves can cause low compression, hard starting, rough running, and loss of power. Restore your Yamaha YFM350 or YFM400 engine's performance with this quality aftermarket valve pair, designed to keep you riding with confidence.

Order your engine valve pair today and get back on the trail with confidence.