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Engine & Performance

Choose from Engine & Performance products for Harley-Davidson, American V-twin and compatible motorcycle applications. Across the range you will find products for engine components. Compatibility varies, so match the stated model, year and technical details before ordering.

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£115.11
£115.11 - £115.11
£115.11
£113.51
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£113.51

Cometic EST Top End Gasket Kit. Evo B.T. 3-13/16" Big Bore – 1992–1999 Evo Big Twin with 3-13/16" Big…

Only 2 left!

Cometic EST Top End Gasket Kit. Evo B.T. 3-13/16" Big Bore – 1992–1999 Evo Big Twin with 3-13/16" Big… With 3.812" bore MLS (Multi-Layer-Steel) .03...

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£115.11
£115.11 - £115.11
£115.11
£113.51
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£113.51
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£120.82
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£120.82
£119.14
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£119.14

Cometic EST Top End Gasket Kit. Twin Cam 4-1/8" Bore – 1999–2017 Twin Cam with 4-1/8" Bore

Only 2 left!

Cometic EST Top End Gasket Kit. Twin Cam 4-1/8" Bore – 1999–2017 Twin Cam with 4-1/8" Bore With MLS (Multi-Layer-Steel) .030" thick head gaskets. T...

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£120.82
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£120.82
£119.14
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£119.14
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£273.75 - £273.75
£273.75
£275.86
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£275.86

Cometic EST Motor Only Gasket Kit. 3-13/16" Big Bore – 1992–1999 Big Twin

Only 2 left!

Cometic EST Motor Only Gasket Kit. 3-13/16" Big Bore – 1992–1999 Big Twin With .040" MLS (Multi Layer Steel) head gaskets. This EST (Extreme-Sealin...

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£273.75 - £273.75
£273.75
£275.86
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£275.86
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£120.81
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£120.81
£119.13
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£119.13

Cometic EST Top End Gasket Kit. Twin Cam 3-7/8" Bore – 1999–2017 95"/103" Twin Cam

Only 2 left!

Cometic EST Top End Gasket Kit. Twin Cam 3-7/8" Bore – 1999–2017 95"/103" Twin Cam With MLS (Multi-Layer-Steel) .051" thick head gaskets. The SLS (...

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£120.81
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£120.81
£119.13
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£119.13
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£115.11
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£115.11
£113.51
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£113.51

Cometic EST Top End Gasket Kit. S&S Evo 4" Bore – All S&S Evo Style Engines with 4" Bore…

Only 2 left!

Cometic EST Top End Gasket Kit. S&S Evo 4" Bore – All S&S Evo Style Engines with 4" Bore… With MLS (Multi-Layer-Steel) .040" thick head gas...

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£115.11
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£115.11
£113.51
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£113.51
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£103.22
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£103.22
£101.79
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£101.79

Cometic Cylinder Head Gasket Set. 4-1/4" .036" MLS – 2002–2007 V-Rod with 4-1/8" Big Bore…

Only 2 left!

Cometic Cylinder Head Gasket Set. 4-1/4" .036" MLS – 2002–2007 V-Rod with 4-1/8" Big Bore… .036" MLS (Multi Layer Steel). MLS consists of a top and...

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£103.22
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£103.22
£101.79
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£101.79
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£214.42 - £214.42
£214.42
£216.07
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£216.07

Cometic EST Top End Gasket Kit. Evo XL 3-3/4" Big Bore – 1991–2003 XL Sportster with 3-3/4" Big…

Only 2 left!

Cometic EST Top End Gasket Kit. Evo XL 3-3/4" Big Bore – 1991–2003 XL Sportster with 3-3/4" Big… With MLS (Multi-Layer-Steel) .040" thick head gask...

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£214.42 - £214.42
£214.42
£216.07
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£216.07
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£115.11
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£115.11
£113.51
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£113.51

Cometic EST Top End Gasket Kit. Evo XL 3-3/4" Big Bore – 1986–1990 4-Speed XL Sportster with…

Out of stock

Cometic EST Top End Gasket Kit. Evo XL 3-3/4" Big Bore – 1986–1990 4-Speed XL Sportster with… With MLS (Multi-Layer-Steel) .040" thick head gaskets...

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£115.11
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£113.51
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£113.51
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£51.20
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£51.20
£48.75
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£48.75

Cometic Cylinder Head Gasket Set. 4-1/8" .051" MLS – 1999–2017 Twin Cam with 4-1/8" Big Bore…

Out of stock

Cometic Cylinder Head Gasket Set. 4-1/8" .051" MLS – 1999–2017 Twin Cam with 4-1/8" Big Bore… .051" thick MLS (Multi Layer Steel). Consists of a to...

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£51.20
£51.20 - £51.20
£51.20
£48.75
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£48.75
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£51.20
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£51.20
£48.75
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£48.75

Cometic Cylinder Head Gaskets 4" Bore .045" MLS – 1999–2017 Twin Cam

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Cometic Cylinder Head Gaskets 4" Bore .045" MLS – 1999–2017 Twin Cam MLS (Multi Layer Steel). Front & rear gasket for one engine. 4.00" bore fi...

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£51.20
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£51.20
£48.75
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£48.75
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£31.00
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£31.00
£29.52
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£29.52

Cometic Gasket Starter Hole Cover. .060" AFM – 1971–1978 FX Models & Other 65-E84…

Only 2 left!

Cometic Gasket Starter Hole Cover. .060" AFM – 1971–1978 FX Models & Other 65-E84… .060" thick AFM (Aluminum Foamet Material). Gasket for the O...

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£29.52
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£29.52
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£63.08
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£63.08
£60.05
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Cometic Cam Cover Gaskets. .060" AFM – 1936–1940 E; EL Knucklehead

Out of stock

Cometic Cam Cover Gaskets. .060" AFM – 1936–1940 E; EL Knucklehead .060" thick AFM (Aluminum Foamet Material). AFM gaskets are made with an aluminu...

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£63.08
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£63.08
£60.05
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£60.05
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£7.49
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£7.49
£6.89
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£6.89

Cometic Pushrod Cover Spring – 1936–2025 Big Twin; 1957–1990 XL…

Out of stock

Cometic Pushrod Cover Spring – 1936–2025 Big Twin; 1957–1990 XL… OEM style reproduction. Used between the spring and seal of the lower pushrod tube...

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£7.49
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£7.49
£6.89
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£6.89
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£51.20
£51.20 - £51.20
£51.20
£48.75
£48.75 - £48.75
£48.75

Cometic Cylinder Head Gasket Set. 3-3/4" .030" MLS – 1984–1999 Big Twin

Only 1 left!

Cometic Cylinder Head Gasket Set. 3-3/4" .030" MLS – 1984–1999 Big Twin .030" thick MLS (Multi Layer Steel). Consists of a top and bottom layer of ...

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£51.20
£51.20 - £51.20
£51.20
£48.75
£48.75 - £48.75
£48.75
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£51.20
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£51.20
£48.75
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£48.75

Cometic Cylinder Head. 3.5" Bore .051" MLS – 1984–1999 Big Twin; 1988–2022 XL…

Only 2 left!

Cometic Cylinder Head. 3.5" Bore .051" MLS – 1984–1999 Big Twin; 1988–2022 XL… .051" thick MLS (Multi Layer Steel). Consists of a top and bottom la...

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£51.20
£51.20 - £51.20
£51.20
£48.75
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£48.75
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£5.25
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£5.25
£4.83
£4.83 - £4.83
£4.83

Cometic Air Cleaner Backing Plate O-ring – Some 1998–2007 Big Twin; Some 2006–2016…

Out of stock

Cometic Air Cleaner Backing Plate O-ring – Some 1998–2007 Big Twin; Some 2006–2016… In aircleaner back plate. Seals breather bolt. OEM replacement ...

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£5.25
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£5.25
£4.83
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£4.83
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£3.22
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£3.22
£2.87
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£2.87

Cometic Oil Pump End Cap O-rings – 1992–1999 Evo Big Twin

Only 2 left!

Cometic Oil Pump End Cap O-rings – 1992–1999 Evo Big Twin 2 used. OEM replacement reference 11241. Fitment 92-99 Evo Big Twin (NU) Product Details ...

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£3.22
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£3.22
£2.87
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£2.87
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£102.25
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£102.25
£98.71
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£98.71

Cometic Gasket Transmission Oil Pan. .060" AFM – 1999–2016 FLT/Touring

Only 2 left!

Cometic Gasket Transmission Oil Pan. .060" AFM – 1999–2016 FLT/Touring .060" AFM (Aluminum Foamet Material). OEM replacement reference 26077-99A. C...

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£102.25
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£102.25
£98.71
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£98.71
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£102.23
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£102.23
£98.69
£98.69 - £98.69
£98.69

Cometic Transmission Oil Pan Gaskets. .060" AFM – 1999–2017 Dyna

Only 2 left!

Cometic Transmission Oil Pan Gaskets. .060" AFM – 1999–2017 Dyna .060" AFM (Aluminum Foamet Material). OEM replacement reference 26702-99A. Cometic...

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£102.23
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£102.23
£98.69
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£98.69
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£27.10
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£27.10
£25.80
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£25.80

Cometic Gasket Transmission Top Cover. AFM – 1999–2005 Dyna

Only 2 left!

Cometic Gasket Transmission Top Cover. AFM – 1999–2005 Dyna AFM (Aluminum Foamette Material). OEM replacement reference 34917-99; 34917-99A; 34917-...

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£27.10
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£27.10
£25.80
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£25.80
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£30.10
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£28.66
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£28.66

Cometic Transmission Bearing Housing Gasket. .032" AFM – 1999–2006 Big Twin

Only 2 left!

Cometic Transmission Bearing Housing Gasket. .032" AFM – 1999–2006 Big Twin .032" thick AFM (Aluminum Foamet Material). OEM replacement reference 3...

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£30.10
£30.10 - £30.10
£30.10
£28.66
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£28.66
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£25.45
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£25.45
£24.23
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£24.23

Cometic Air Cleaner Housing to Filter Element Gasket. AFM – 1999–2001 FLT/Touring with…

Only 2 left!

Cometic Air Cleaner Housing to Filter Element Gasket. AFM – 1999–2001 FLT/Touring with… AFM. Used between the air filter backplate assembly and the...

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£25.45
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£25.45
£24.23
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£24.23
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£21.65
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£21.65
£20.61
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£20.61

Cometic Throttle Body to Air Cleaner Housing Gasket. AFM – 1999–2001 Twin Cam Delphi Fuel Injected…

Only 2 left!

Cometic Throttle Body to Air Cleaner Housing Gasket. AFM – 1999–2001 Twin Cam Delphi Fuel Injected… AFM (Aluminum Foamet Material). Induction modul...

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£21.65
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£21.65
£20.61
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£20.61
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£19.71
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£19.71
£18.76
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£18.76

Cometic Carb/Throttle Body to Air Cleaner Housing. AFM – CV Carburetor: 1995–2000 Evo Big Twin…

Only 1 left!

Cometic Carb/Throttle Body to Air Cleaner Housing. AFM – CV Carburetor: 1995–2000 Evo Big Twin… .060" AFM. Fits between carb & air cleaner hous...

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£19.71
£19.71 - £19.71
£19.71
£18.76
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£18.76
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