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Cylinder Head Service Kit, 0.380" Lift, Yamaha®, YZ™ 450F, 2003-'05 / WR™450, 2003-'06

Cylinder Head Service Kit, 0.380" Lift, Yamaha®, YZ™ 450F, 2003-'05 / WR™450, 2003-'06


Regular price $583.51 USD
Regular price $583.51 USD Sale price $583.51 USD
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California Prop 65

KPMI® is proud to introduce full CYLINDER HEAD SERVICE KITS. These kits contain all items to completely refresh and upgrade cylinder heads for popular Dirt / MX and Side x Side models with KPMI’s top quality racing valvetrain components.


  • Save time money on your next cylinder head rebuild
  • One package, everything you need for factory recommended valvetrain service
  • Double your service life over OEM using KPMI® Valvetrain products
  • Kitted with value added savings

Kit Includes:

  • Dual Spring Titanium Retainer Spring Kit, Which Allows for 0.445" Valve Lift
  • Top End Gasket Kit by Cometic
  • KPMI® C674 Bronze Standard Valve Guides
  • KPMI® S.S. White Diamond® Valves, Stock Head Dia.

The product image may not be accurate on the page. Please refer to the description and specifications before purchasing.

Installation Instructions Click Here
Type Intake/ Exhaust
Retainer Material Titanium 
Valve Lift 0.380"
Installed Height 1.105"
Seat Pressure 39#
Open Pressure 86#
Intake @ Lift 0.380"
Valve Type  Intake/ Exhaust
Valve Material White Diamond® Stainless
Coating Hard Chrome
Intake Head Diameter 27.00mm/ 1.063"
Intake Stem Diameter 4.5mm/ 0.1765"
Intake Tulip 15º
Intake Overall Length Intake (Outer)- 3.040"
Intake (Center)- 3.000"
Exhaust Head Diameter 28.00mm/ 1.102"
Exhaust Stem Diameter 5.0mm/ 0.1956"
Exhaust Tulip 20º
Exhaust Overall Length 2.955"
Remarks Standard
Guide Type Intake/ Exhaust
Guide Material C674 Bronze
Reference See Figure 1
Intake Outside Dia.: (G) 0.3957" / Std.
Intake (A) 0.350"
Intake (B) 0.385"
Intake (C) 0.480"
Intake (D) 0.680"
Intake (E) 0.430"
Intake (F) 0.1768"
Exhaust Outside Dia.: (G) 0.3957" / Std.
Exhaust (A) 0.350"
Exhaust (B) 0.385"
Exhaust (C) 0.510"
Exhaust (D) 0.680"
Exhaust (E) 0.430"
Exhaust (F) 0.1961"
Unique Identifier No. FR327789_01GAUSt


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