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Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01

  • Part #:
    140670
  • Manufacturer Part #:
    21003-K01

MSRP Price: $649.95

Our Price: $584.96

You Save:
$64.99 (10%)
Ships In 4-5 Business Days

Overview of Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01

  • Direct bolt-on, ready-to-install cylinders; require no replating and look virtually identical to the OEM
  • Nickel Silicon Carbide plated for long life
  • Honed to exact size for easy piston installation
  • Big bore cylinders do not require machine work (unless noted)
  • Big bore cylinder kits come complete with gaskets, cylinder, piston, rings, pin and clips


Included Items:

(1) Cylinder head

(1) Piston

(1) Wrist pin

(2) Cir-clips

(1) Top ring

(2) Oil rings

(1) Spacer ring

(1) Cylinder head gasket

(1) Cylinder gasket

(1) Exhaust gasket

(1) Case gasket

Instructions

 

Specs for Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01

Type Cylinder Kit
Type Top End Kit w/Cylinder
Units Each
Weight 4.05 lbs

Cross reference number(s):

09310174

Specs for Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01

Type Cylinder Kit
Type Top End Kit w/Cylinder
Units Each
Weight 4.05 lbs

Fitment for Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01

See if this part fits your ride

Part 140670 fits the following machines

Yamaha
  • 2009 Yamaha YZ450F
  • 2008 Yamaha YZ450F
  • 2007 Yamaha YZ450F
  • 2006 Yamaha YZ450F
  • 2006 Yamaha YZ450FSP 50th Anniversary Edition
5.0 / 5.0
2 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
2
0
0
0
0
Fit
5.0 / 5
Quality
4.5 / 5
Style
4.5 / 5
Value
4.5 / 5
Fit
5 / 5
Quality
5 / 5
Style
5 / 5
Value
5 / 5
Great up-grade
I put this big bore kit on my bike , and wow everything fit excellent and it was so easy. I got so much more power now when i'm up in the mountains and over on the track. It was well worth the money and it was so quick to change out. I'm satisfied and happy with my choice.
March 2, 2010
Fit
5 / 5
Quality
4 / 5
Style
4 / 5
Value
4 / 5
No Review Title Entered By User
Great power increase in my WR450. The C-clips for the piston wrist pin are a bit difficult. I think the design would need a lock ring...All over good choice. Recommend rejetting your carb and a quick shot excellerator pump cover for best performance.
August 7, 2011
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Instructions and Manuals for Cometic +3mm Big Bore Complete Cylinder Kit - 478cc - 21003-K01