2026 KPMI Full Catalog V1 - Flipbook - Page 324
YAMAHA 1.8L 4V WATERCRAFT 2008-'23
®
YAMAHA
Valve Spring Kit • High Performance Lightweight Racing
KPMI P/N
Type
Max Valve Lift Installed Height
Seat Pressure
Open Pressure
@ Lift
85#
221#
.425”
Intake
80-81000
.425”
1.375"
Exhaust
Kit Includes
KPMI P/N
16
Type
Titanium Retainers
16
CrSi Valve Springs
Max Valve Lift Installed Height
16
H. T. Steel Basewashers
Seat Pressure
Open Pressure
@ Lift
85#
221#
.425”
Intake
80-81600
.425”
1.375"
Exhaust
Kit Includes
16
H.T. Steel Retainers
16
CrSi Valve Springs
16
H. T. Steel Basewashers
• Spring Kit is designed with increased spring rate and higher lift compatibility over the stock components
• Spring Kit is speci昀椀cally designed for high boost / high RPM applications
• CNC'd Titanium or H.T. Steel Retainers and Cr-Si dual springs provide valvetrain control at high RPM with high performance camshaft compatibility
Valves • White Diamond® • Hard Chrome Stems • Inconel®
Stem Diameter
Tulip
O. L.
Remarks
1.339"
0.2159"
15º
3.560"
Standard
(Stainless)
1.142"
0.2154"
25º
3.535"
Standard
(Inconel®)
KPMI P/N
Type
Head Diameter
80-81012H
Intake
34.00mm
*80-81016K
Exhaust
29.00mm
*Inconel® is classi昀椀ed as a “Super Alloy”, meaning that it is designed to survive under the most extreme temperatures and pressures, where other valves will
begin to burn, corrode, or completely fail. This is the material of choice for high output engines running turbos, superchargers, nitromethane, or nitrous.
Valve Guides • C630 Bronze
A
B
C
D
E
0.435”
0.495”
0.730"
1.020"
0.475"
F
G
Intake
Exhaust
80-81020
0.2154" 0.3774" / Std.
+0.001”
80-81021
+0.002”
80-81022
+0.010”
80-81029
Valve Guide Seals • Viton®
Stem Diameter
5.5mm
O.L
0.333"
306
order 650-557-2046
Seal O.D.
0.455"
Seal Style
2
A
0.365”±0.002”
Designed for these guide specs
B
C
0.325”
0.120”
D
0.235”
Type
Intake
Exhaust
Part Number
Quantity
Quantity Discount
71040-4
Pkg. of 4
0%
71040-8
Pkg. of 8
0%
71040-16
Pkg. of 16
Less- 10%
71040-50
Pkg. of 50
Less- 15%
71040-100
Pkg. of 100
Less- 20%
