ORO2U Dirt Catalogue - Section E - Engine and Performance.

Piston Kits

Namura

Namura N Forged 4-Stroke Piston Kits N amura Forged pistons offer dyno-proven gains in performance and durability over industry-standard 4032 forged pistons. Namura’s exclusive forged alloy offers lower expansion rates, allowing for tighter build tolerances and superior tensile and yield strength at operating temperatures. A ll new Forged pistons come with Namura’s signature features: 100% CNC-machine piston domes, hard anodized domes for reduced carbon build-up and heat resistance and M0S2 coated skirts for excellent break-in protection and properties.

YAMAHA

Years

Size

Piston Kit

Oem Ref

Piston Rings

Small End Bearing

PW 50 YZ 65 BW 80 BW 80 PW 80 YZ 80 YZ 85 DT 125

1981 - 24 40mm 56-W938+000.NT 2018 - 24 43.5mm 56-W9991.A.NT 1986 - 88 47mm 56-W939+000.NT

– – – –

– –

56-7996.DR

56-R713 56-R713 56-R713

56-827.SI 56-827.SI 56-827.SI 56-821.SI 56-821.SI

1990

47mm 56-W939+000.NT

1983 - 06 47mm 56-W939+000.NT 5GH-11631-00

1993 - 01 47mm 56-W646+00A.NT 4ES-11631-01-AO 56-R703 2002 - 25 47.5mm 56-W646+050A.NT 5PA-11631-00-BO 56-R702

56-W0078.5600 ** 56-W253.000.NT 56-W224.000.NT 56-W253.000.NT

1978 - 81 1982 - 86 1991 - 06 1985 - 90

56mm 56mm 56mm 56mm

– – – –

– – – –

DT 125 LC

56-844.NT

DT 125 E/R/X

RD 125 LC

56-844.NT 56-836.SI 56-814.SI 56-814.SI 56-814.SI 56-814.SI

1997 - 00 54mm 56-W859.A.NT *

4XM-11631-30-BO 56-R704 ** 4XM-11631-30-BO 56-R704 **

YZ 125 YZ 125 YZ 125 YZ 125

54mm 56-W859.A.NT *

2001

2002 - 04 54mm 56-W797.A.NT * 2005 - 24 54mm 56-W845.A.NT * 2020 - 24 54mm 56-W845.A.NT * 1992 - 98 68mm 56-W677.A.NT 1992 - 98 68mm 56-W677.A.NT 1999 - 24 66.4mm 56-W742.A.NT 2016 - 24 66.4mm 56-W742.A.NT

56-R704 ** 56-R704 ** 56-R704 **

5NY-11631-01-A0

YZ 125X WR 250

4SR-11631-00-BO 56-R715 4SR-11631-00-BO 56-R715 5MW-11631-00-BO 56-R700 5MW-11631-00-BO 56-R700

YZ 250 YZ 250

56-809.SI 56-801.SI 56-801.SI

YZ 250X

** Please Note; Piston brand for particular item is not Namura

4-Stroke TT 225L TTR 225 TTR 230 WR 250F

Piston Type

Years

Size

Piston Kit

Oem Ref

Piston Rings

Small End Bearing

N Forged N Forged N Forged N Forged

1999

70mm 56-W1030+00A.NT

– – – – – – – – – – –

1999 - 04 70mm 56-W1030+00A.NT 2005 - 24 70mm 56-W1030+00A.NT 2001 - 04 77mm 56-W022+00A.NF 2005 - 13 77mm 56-W9702.A 2005 - 13 77mm 56-W9702.A.NF 2015 - 19 77mm 56-W4961.A.NT 2020 - 24 77mm 56-W8812.A.NT 2001 - 04 77mm 56-W022+00A.NF 2005 - 13 77mm 56-W9702.A 2005 - 13 77mm 56-W9702.A.NF 2014 - 18 77mm 56-W4961.A.NT 2019 - 24 77mm 56-W8812.A.NT 2015 - 19 77mm 56-W4961.A.NT 2020 - 23 77mm 56-W8812.A.NT 1987 - 88 83mm 56-W4419+00A.NT 2003 - 15 95mm 56-W4785.A.NT 2003 - 15 95mm 56-W4785.A.NT.F 2016 - 20 97mm 56-W4963.A.NT 2016 - 20 97mm 56-W4963.A.NT.F 2003 - 09 95mm 56-W4785.A.NT 2003 - 09 95mm 56-W4785.A.NT.F 2010 - 13 97mm 56-W261.A.NT 2010 - 13 97mm 56-W261.A.NT.F 2014 - 17 97mm 56-W4963.A.NT 2014 - 19 97mm 56-W4963.A.NT.F 2016 - 18 97mm 56-W4963.A.NT 2016 - 19 97mm 56-W4963.A.NT.F 1984 - 04 95mm 56-W4797+00A.NT 1984 - 04 95mm 56-W4797+00A.NT 1984 - 04 95mm 56-W4797+00A.NT 1991 - 98 100mm 56-W8507+00A.NT

– – – – – – – –

56-R728 56-R728 56-R728 56-R728 56-R728 56-R728 56-R728 56-R728

WR 250F Hi-Comp. 13.5:1

Hyperdryve

Hi-Comp. 13.5:1

N Forged N Forged N Forged N Forged

WR 250F WR 250F YZ 250F

YZ 250F Hi-Comp. 13.5:1

Hyperdryve

Hi-Comp. 13.5:1

N Forged N Forged N Forged N Forged N Forged

YZ 250F YZ 250F YZ 250FX YZ 250FX BW 350T

56-R728

– – – – – – – – – – – – – – – – –

56-R757 56-R759 56-R759

– – – – – – – – – – – – – – – – –

WR 450F Comp. 12.5:1

Hyperdryve

Comp. 12.5:1

N Forged

WR 450F Comp. 12.5:1

Hyperdryve

56-R7706.NT 56-R7706.NT

Comp. 12.5:1

N Forged

YZ 450F Comp. 12.5:1

Hyperdryve

56-R759 56-R759

Comp. 12.5:1

N Forged

YZ 450F Comp. 12.5:1

Hyperdryve

56-R7706.NT 56-R7706.NT 56-R7706.NT 56-R7706.NT 56-R7706.NT 56-R7706.NT

Comp. 12.5:1

N Forged

YZ 450F Comp. 12.5:1

Hyperdryve

Comp. 12.5:1

N Forged

YZ 450FX Comp. 12.5:1

Hyperdryve

Comp. 12.5:1

N Forged

XT 600

56-R760 56-R760 56-R760 56-R761

TT 600/R XTZ 600

XTZ 660 Tenere

* Note; Most Kits are available from standard size up to +2.00mm over size *

*Please visit our website for current prices

E-mail: sales@oro2u.com

www.oro2u.com

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