2026 KPMI Full Catalog V1 - Flipbook - Page 300
YAMAHA VARIOUS 400-450cc 1998-'13
®
YAMAHA
•
•
•
WR™ 400F 1998-'00
WR™ 426F 2001-’02
WR™ 450F 2003-’06
•
•
•
•
YFZ™ 450 2004-'13
YZ™ 400F 1998-'99
YZ™ 426F 2000-'02
YZ™ 450F 2003-'05
Cylinder Stud Kit • H.T. Steel
KPMI P/N
80-82650
Quantity
Body Dia.
“C”
“A”
“B”
2
0.358”
6.7”
1.42”
1.42”
Quantity
Body Dia.
“D”
“E”
“F”
0.358”
6.5”
H. T. Steel Studs
4
2
Kit Includes
4
1.42”
1.42”
H. T. Steel Nuts
4
H. T. Steel Washers
KPMI® Cylinder Studs are made from 180,000 psi yield strength, 昀椀ne grain, heat treated, aircraft grade alloy steel. When you want a stud that meets proof-stress
and maximizes clamping force, look no further. KPMI® “rolls” the threads, heat treats and then centerless grinds the entire body of the stud. Rolling the threads
creates the toughest and strongest thread possible and centerless grinding removes notch sensitivity. The 昀椀nal process for all KPMI® Studs is to encase the
entire stud with premium corrosion resistant treatment of Black Oxide. Congratulations on your choice to purchase a stud that meets and exceeds your stockreplacement of high-performance needs!
Cylinder Head Nuts
KPMI P/N
Hex Pattern
Material
O. L.
F. D.
Thread
Quantity
41010-4
12mm
Material
0.400”
0.700”
M10 x 1.25
Pkg. of 4
Replacement nuts for Stud Kit, #80-82650, but can be used for general purpose (see diagram for detail)
KPMI® nuts are single point machined from high tensile strength Aircraft Alloy Steel. During the machining process close tolerances and smooth surface 昀椀nishes are
maintained. Two critical factors for achieving correct 昀椀t and torque. After machining, the nuts are heat treated to a speci昀椀c depth. This creates hard, wear resistant working
surfaces, while retaining a ductile core to prevent cracking under load. The premium black oxide treatment provides excellent corrosion resistance and appearance.
YAMAHA VARIOUS 450cc 2003-'25
®
•
•
WR™ 450 2003-'15
YZ™ 450F 2003-'09
•
•
•
YFZ™ 450 2004-'09
YFZ™ 450X 2008-'11
YFZ™ 450R & SE 2009-'25
Valve Spring Kit • Lightweight Racing
KPMI P/N
80-80206
Type
Max Valve Lift Installed Height
Intake
Exhaust
Kit Includes
.380”
1.105"
.380”
1.105"
Seat Pressure
Open Pressure
@ Lift
39#
86#
.380"
86#
.380"
39#
3
In Titanium Retainers
3
In CrSi Valve Springs
3
In H. T. Steel Basewashers
2
Ex Titanium Retainers
2
Ex CrSi Valve Springs 2
Ex H. T. Steel Basewashers
3
In Viton® Seals
2
Ex Viton® Seals
Top End Service Kit for YZ 450F 2003-’05 / WR 450 2003-’06
Piston
Bore Size
Type
Max
Valve Lift
Installed
Height
Seat
Pressure
Open
Pressure
@ Lift
80-81900 95.00mm
Intake
Exhaust
.380”
.380”
1.105"
1.105"
39#
39#
86#
86#
.380"
.380"
In Titanium Retainers
3
In CrSi Valve Springs
KPMI P/N
3
3
In H. T. Steel Basewashers
2
Kit Includes
Ex Titanium Retainers 2 Ex CrSi Valve Springs 2 Ex H. T. Steel Basewashers
In Std. (Outer)
In Std. (Center)
Ex Std.
2
1
2
White Diamond® Valves
White Diamond® Valves
White Diamond® Valves
3
2
In Viton® Seals
Ex Viton® Seals
1
High Performance Piston Kit
1
Top End Gasket Kit
282
IMPORTANT NOTE: The 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.
order 650-557-2046
