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Top End Service Kit, Stainless Conv., 0.395" Lift, Yamaha®, WR™ / YZ™ 250F, 2014-2016

Top End Service Kit, Stainless Conv., 0.395" Lift, Yamaha®, WR™ / YZ™ 250F, 2014-2016


Regular price $732.91 USD
Regular price $732.91 USD Sale price $732.91 USD
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California Prop 65

Kit Includes:

  • Piston, Rings, Clips and Pin – (2618 Alloy Fully CNC Machined Race Piston)
  • Complete Top End Gasket Kit by Cometic™
  • KPMI® S.S. Black Diamond™ Valves, Stock Head Dia. (All Valves)
  • Complete Dual Spring / High Performance Titanium Retainer Spring Kit


  • Complete piston assembly, gasket kit and valves to rebuild or service your bikes top end
  • Cost saving built into purchasing these components as a kit
  • Designed specifically for the performance demands of MX Bikes and Quads
  • Pistons designed to maintain stock compression
  • 2618 Alloy Fully CNC Machined Piston with performance skirt coating
  • KPMI® High Performance Valvetrain is known to outlast OEM by twice the service life
  • Lightweight Racing Spring Kit compatible with high performance cams

IMPORTANT NOTEThe piston assembly (piston, rings, pin and pin clips) in this kit are designed to work together as a system. When used complete, the piston assembly can be used as an OEM replacement. The individual components are NOT INTERCHANGEABLE with O.E.M. piston assembly components.

Installation Instructions Click Here
Piston Bore Size 77.00mm
Type Intake/ Exhaust
Retainer Material Titanium 
Intake Valve Lift 0.395"
Intake Installed Height 1.150"
Intake Seat Pressure 55#
Intake Open Pressure 151#
Intake @ Lift 0.395"
Exhaust Valve Lift 0.370"
Exhaust Installed Height 1.100"
Exhaust Seat Pressure 46#
Exhaust Open Pressure 119#
Exhaust @ Lift 0.370"
Valve Type  Intake/ Exhaust
Valve Material Black Diamond™ Stainless
Coating Black Nitroneg
Intake Head Diameter 31.00mm/ 1.220"
Intake Stem Diameter 5.0mm/ 0.1962"
Intake Tulip 18º
Intake Overall Length 3.265"
Exhaust Head Diameter 25.00mm/ 0.984"
Exhaust Stem Diameter 4.5mm/ 0.1760"
Exhaust Tulip 30º
Exhaust Overall Length 3.235"
Remarks Standard
Unique Identifier No. FR327789_01GAUSt
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