ProX Exhaust Valve & Spring Kit

Item Number: 347613


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Product Description


ProX Exhaust Valve & Spring Kit

ProX Steel Exhaust Valve and Spring Kits are offered as an alternative where the OEM application uses Titanium Valves. Titanium is a very exotic material that requires a strict installing procedure to make it work well. The OEM Titanium valve quality in general is rather poor while high-end titanium valves are very expensive. Titanium valves need to be replaced at a regular base, resulting in many expensive rebuilds.

ProX has now developed Steel Exhaust Valve and Spring Kits, containing a set of steel exhaust valves plus a set of specially designed stronger valve springs. The ProX kit replaces the OEM valves and valve springs and can be installed using the OEM retainers, bases and valve seats. The steel valves offer increased durability and easily extends 3 times the lifespan of the OEM Titanium valves. Due to the extra weight of the steel a heavier valve spring must be used!


  • Steel valves for increased durability and less wear under extreme conditions.
  • Nitrided valves offer high micro hardness while surface finish reduces friction between stem and guide.
  • Special stronger valve springs deal with the extra weight of the steel valves.
  • Spring are made from premium chrome vanadium steel for higher performance and durability under high RPM.
  • Fully rebuildable with OEM retainers, bases and seals without the need of any further engine modifications.
  • Comes as complete package for quick, easy and cost efficient replacement.

Spec Details
Country Of Origin Varies (make selection above)
Material Varies (make selection above)
Position Exhaust
Valve Position Varies (make selection above)

Vehicle Fitment

Fitment is guaranteed or your money back plus free return shipping. Don't waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.


  • 250 SX-F 2008-2013
  • 350 SX-F 2013-2015


  • YZ250F 4-Stroke 2013-2016
  • YZ450F 2014-2015

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