Skip to content
Find us Hours of Business Email Us Shipping Cookie policy Returns Terms & Conditions Privacy Policy Refunds

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.

Filters

Save 5% Save %
£24.27
£24.27 - £24.27
£24.27
£23.11
£23.11 - £23.11
£23.11

Cometic Cylinder Base Gasket. Rear. .031" Fiber – 1963–1965 Panhead; 1966–1984 Shovelhead

Only 2 left!

Cometic Cylinder Base Gasket. Rear. .031" Fiber – 1963–1965 Panhead; 1966–1984 Shovelhead Rear gasket. .031" fiber; a premium hi-temperature; hi-de...

View full details
£24.27
£24.27 - £24.27
£24.27
£23.11
£23.11 - £23.11
£23.11
Save 5% Save %
Sold out
£24.27
£24.27 - £24.27
£24.27
£23.11
£23.11 - £23.11
£23.11

Cometic Cylinder Base Gasket. Front. .031" Fiber – 1963–1965 Panhead; 1966–1984 Shovelhead

Out of stock

Cometic Cylinder Base Gasket. Front. .031" Fiber – 1963–1965 Panhead; 1966–1984 Shovelhead Front gasket. .031" fiber; a premium hi-temperature; hi-...

View full details
£24.27
£24.27 - £24.27
£24.27
£23.11
£23.11 - £23.11
£23.11
Sold out
Sold out
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38

Cometic Cylinder Base Gasket Set FR/RR. .020" RCS – 1936–1947 61"/74" Knucklehead; 1937–1948…

Out of stock

Cometic Cylinder Base Gasket Set FR/RR. .020" RCS – 1936–1947 61"/74" Knucklehead; 1937–1948… Front & rear set. .020" RCS (Rubber Coated Steel)...

View full details
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38
Sold out
Sold out
£13.21
£13.21 - £13.21
£13.21
£12.58
£12.58 - £12.58
£12.58

Cometic Cylinder Base Gasket Set FR/RR .020" Fiber – 1936–1947 61"/74" Knucklehead; 1937–1948…

Out of stock

Cometic Cylinder Base Gasket Set FR/RR .020" Fiber – 1936–1947 61"/74" Knucklehead; 1937–1948… Front & rear set. .020" thick fiber; a premium h...

View full details
£13.21
£13.21 - £13.21
£13.21
£12.58
£12.58 - £12.58
£12.58
Sold out
Sold out
£48.47
£48.47 - £48.47
£48.47
£46.15
£46.15 - £46.15
£46.15

Cometic Cylinder Head Gasket Set. .043" CMF-20 – 1936–1947 Knucklehead

Out of stock

Cometic Cylinder Head Gasket Set. .043" CMF-20 – 1936–1947 Knucklehead .043" thick CMF-20; a gasket with a perforated stainless steel core with a h...

View full details
£48.47
£48.47 - £48.47
£48.47
£46.15
£46.15 - £46.15
£46.15
Sold out
Save 5% Save %
£21.56
£21.56 - £21.56
£21.56
£20.53
£20.53 - £20.53
£20.53

Cometic Manifold Intake Seals. Extra Thin for S&S Manifolds – 1984–2017 Big Twin; 1986–2022 XL…

Only 2 left!

Cometic Manifold Intake Seals. Extra Thin for S&S Manifolds – 1984–2017 Big Twin; 1986–2022 XL… Thinner than stock. 1.880" I.D. Viton. Used bet...

View full details
£21.56
£21.56 - £21.56
£21.56
£20.53
£20.53 - £20.53
£20.53
Save 5% Save %
Save 1% Save %
£168.08
£168.08 - £168.08
£168.08
£165.75
£165.75 - £165.75
£165.75

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2006 FLT/Touring / FLT/Touring

Only 2 left!

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2006 FLT/Touring / FLT/Touring This EST (Extreme-Sealing-Technology) gasket set is complete with a...

View full details
£168.08
£168.08 - £168.08
£168.08
£165.75
£165.75 - £165.75
£165.75
Save 1% Save %
Sold out
£168.11
£168.11 - £168.11
£168.11
£165.77
£165.77 - £165.77
£165.77

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2006 FLT/Touring / FLT/Touring

Out of stock

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2006 FLT/Touring / FLT/Touring This EST (Extreme-Sealing-Technology) gasket set is complete with a...

View full details
£168.11
£168.11 - £168.11
£168.11
£165.77
£165.77 - £165.77
£165.77
Sold out
Save 1% Save %
£168.11
£168.11 - £168.11
£168.11
£165.77
£165.77 - £165.77
£165.77

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2005 Dyna; 2000–2006 Softail

Only 2 left!

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2005 Dyna; 2000–2006 Softail This EST (Extreme-Sealing-Technology) gasket set is complete with all...

View full details
£168.11
£168.11 - £168.11
£168.11
£165.77
£165.77 - £165.77
£165.77
Save 1% Save %
Save 1% Save %
£168.08
£168.08 - £168.08
£168.08
£165.75
£165.75 - £165.75
£165.75

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2005 Dyna; 2000–2006 Softail

Only 2 left!

Cometic EST Motor Gasket Kit. 4-1/8" Bore – 1999–2005 Dyna; 2000–2006 Softail This EST (Extreme-Sealing-Technology) gasket set is complete with all...

View full details
£168.08
£168.08 - £168.08
£168.08
£165.75
£165.75 - £165.75
£165.75
Save 1% Save %
Save 8% Save %
£7.14
£7.14 - £7.14
£7.14
£6.57
£6.57 - £6.57
£6.57

Cometic Pushrod Cover Seal Kit. Rubber – 1948–1965 Panhead; 66-E79 Shovelhead

Only 2 left!

Cometic Pushrod Cover Seal Kit. Rubber – 1948–1965 Panhead; 66-E79 Shovelhead Flat rubber seals. Fits as a direct replacement for the OEM style cor...

View full details
£7.14
£7.14 - £7.14
£7.14
£6.57
£6.57 - £6.57
£6.57
Save 8% Save %
Sold out
£11.77
£11.77 - £11.77
£11.77
£11.21
£11.21 - £11.21
£11.21

Cometic Transmission Main Shaft – 2006–2017 Dyna; 2007–2025 Softail…

Out of stock

Cometic Transmission Main Shaft – 2006–2017 Dyna; 2007–2025 Softail… OEM replacement reference 12074. Fitment 06-17 (NU) Dyna; 07-25 Softail; 07-25...

View full details
£11.77
£11.77 - £11.77
£11.77
£11.21
£11.21 - £11.21
£11.21
Sold out
Save 5% Save %
£46.55
£46.55 - £46.55
£46.55
£44.32
£44.32 - £44.32
£44.32

Cometic Primary Gasket & Seal Kit. AFM – 1991–2003 XL Sportster

Only 2 left!

Cometic Primary Gasket & Seal Kit. AFM – 1991–2003 XL Sportster These AFM (Aluminum Foamette Material) gaskets feature an aluminum core with a ...

View full details
£46.55
£46.55 - £46.55
£46.55
£44.32
£44.32 - £44.32
£44.32
Save 5% Save %
Save 5% Save %
£46.55
£46.55 - £46.55
£46.55
£44.32
£44.32 - £44.32
£44.32

Cometic Primary Gasket & Seat Kit. AFM – 1986–1990 XL Sportster

Only 2 left!

Cometic Primary Gasket & Seat Kit. AFM – 1986–1990 XL Sportster These AFM (Aluminum Foamette Material) gaskets feature an aluminum core with a ...

View full details
£46.55
£46.55 - £46.55
£46.55
£44.32
£44.32 - £44.32
£44.32
Save 5% Save %
Save 5% Save %
£18.49
£18.49 - £18.49
£18.49
£17.60
£17.60 - £17.60
£17.60

Cometic Upper Rocker Cover Gasket. Rubber (2) – 2004–2006 XL Sportster

Only 2 left!

Cometic Upper Rocker Cover Gasket. Rubber (2) – 2004–2006 XL Sportster 04-06 style with elongated holes. Will retrofit to 91-03 models where it is ...

View full details
£18.49
£18.49 - £18.49
£18.49
£17.60
£17.60 - £17.60
£17.60
Save 5% Save %
Sold out
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38

Cometic Cylinder Base Gaskets. RCS 3-5/8" Big Bore (Pr) – 1963–1965 Panhead; 1966–1984 Shovelhead.…

Out of stock

Cometic Cylinder Base Gaskets. RCS 3-5/8" Big Bore (Pr) – 1963–1965 Panhead; 1966–1984 Shovelhead.… Front & rear gasket for one engine. .020" t...

View full details
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38
Sold out
Sold out
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38

Cometic Cylinder Base Gasket Set FR/RR. .020" RCS – 1963–1965 Panhead; 1966–1984 Shovelhead

Out of stock

Cometic Cylinder Base Gasket Set FR/RR. .020" RCS – 1963–1965 Panhead; 1966–1984 Shovelhead Front & rear gasket set. With one oil hole. .020" t...

View full details
£27.71
£27.71 - £27.71
£27.71
£26.38
£26.38 - £26.38
£26.38
Sold out
Save 5% Save %
£51.20
£51.20 - £51.20
£51.20
£48.75
£48.75 - £48.75
£48.75

Cometic Cylinder Head. 3" Bore .030" MLS – 1986–2022 XL883

Only 2 left!

Cometic Cylinder Head. 3" Bore .030" MLS – 1986–2022 XL883 .030" MLS (Multi Layer Steel). Stock 3" bore. MLS (Multi Layer Steel) consists of a top ...

View full details
£51.20
£51.20 - £51.20
£51.20
£48.75
£48.75 - £48.75
£48.75
Save 5% Save %
Sold out
£16.49
£16.49 - £16.49
£16.49
£15.70
£15.70 - £15.70
£15.70

Cometic Starter to Inner Primary – 2007–2026 Softail; 2006–2017 Dyna…

Out of stock

Cometic Starter to Inner Primary – 2007–2026 Softail; 2006–2017 Dyna… Starter motor to inner primary housing. OEM replacement reference 27444-00Y F...

View full details
£16.49
£16.49 - £16.49
£16.49
£15.70
£15.70 - £15.70
£15.70
Sold out
Sold out
£74.82
£74.82 - £74.82
£74.82
£72.23
£72.23 - £72.23
£72.23

Cometic Oil Seal 6Th Gear Transmission – 2007–2026 Softail; 2006–2017 Dyna…

Out of stock

Cometic Oil Seal 6Th Gear Transmission – 2007–2026 Softail; 2006–2017 Dyna… 1 used. OEM replacement reference 12077. Fitment 07-26 Softail; 06-17 (...

View full details
£74.82
£74.82 - £74.82
£74.82
£72.23
£72.23 - £72.23
£72.23
Sold out
Sold out
£21.05
£21.05 - £21.05
£21.05
£20.05
£20.05 - £20.05
£20.05

Cometic Gasket Transmission to Engine – 2008–2017 Dyna; 2007–2016 FLT/Touring

Out of stock

Cometic Gasket Transmission to Engine – 2008–2017 Dyna; 2007–2016 FLT/Touring Transmission to engine interface gasket. OEM replacement reference 35...

View full details
£21.05
£21.05 - £21.05
£21.05
£20.05
£20.05 - £20.05
£20.05
Sold out
Save 5% Save %
£27.04
£27.04 - £27.04
£27.04
£25.75
£25.75 - £25.75
£25.75

Cometic Gasket Transmission Top Cover. .060" AFM – 2007–2017 Softail; 2006–2017 Dyna…

Only 2 left!

Cometic Gasket Transmission Top Cover. .060" AFM – 2007–2017 Softail; 2006–2017 Dyna… .060" thick AFM (Aluminum Foamette Material). OEM replacement...

View full details
£27.04
£27.04 - £27.04
£27.04
£25.75
£25.75 - £25.75
£25.75
Save 5% Save %
Sold out
£29.01
£29.01 - £29.01
£29.01
£27.62
£27.62 - £27.62
£27.62

Cometic Gasket Transmission End Cover. .060" AFM – 2007–2024 Softail; 2006–2017 Dyna…

Out of stock

Cometic Gasket Transmission End Cover. .060" AFM – 2007–2024 Softail; 2006–2017 Dyna… .060" thick AFM (Aluminum Foamet Material). OEM replacement r...

View full details
£29.01
£29.01 - £29.01
£29.01
£27.62
£27.62 - £27.62
£27.62
Sold out
Save 5% Save %
£30.10
£30.10 - £30.10
£30.10
£28.66
£28.66 - £28.66
£28.66

Cometic Gasket Transmission Bearing Housing. .032" AFM – 2007–2024 Softail; 2006–2017 Dyna…

Only 2 left!

Cometic Gasket Transmission Bearing Housing. .032" AFM – 2007–2024 Softail; 2006–2017 Dyna… .032" thick AFM (Aluminum Foamet Material). Used betwee...

View full details
£30.10
£30.10 - £30.10
£30.10
£28.66
£28.66 - £28.66
£28.66
Save 5% Save %

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare

Compare