COMETIC

Cometic Gasket Kits for Harley-Davidson, Dirt Bikes and ATVs

Cometic is a gasket catalog split down the middle. About 580 of the roughly 1,160 listings name a Harley-Davidson engine, from Panhead to M8, and about 410 name a Honda, Yamaha, Suzuki, Kawasaki, KTM family or Polaris machine. Most sit in Gaskets, Seals & Kits (about 750), with about 150 in transmission Gaskets & Seals and about 90 in UTV | ATV Gaskets, Seals & Kits.

Cometic's own About page says the company was founded in 1989 by four partners, including current founder and CEO Bob Gorman, and works from a research and manufacturing center in Concord, Ohio.

Harley-Davidson engines

Titles name the engine family and the years, and head gaskets add the bore and thickness. About 120 titles mention M8, around 110 Twin Cam, 85 Evo and 105 Sportster/XL, with smaller runs for Shovelhead, Panhead and Buell.

Complete and motor kits. The M8 motor gasket kit C10250, the complete engine/primary kit for '17-'24 models and the 3.937" Twin Cam kit for '99-'06 are the whole-engine listings. Older engines have them too, such as the 4-speed Shovelhead kit, the 3.250" XL kit for '57-'71 and the Buell kit for '02-'10.

Head and base gaskets. About 120 titles are head gaskets. Twin Cam examples are the 3.875" x .030" for 95"/103" engines and the 3.750" x .040" for 88"/96". M8 has bore-specific listings, like the 4.250" cylinder head gasket and the 4.250" center-cooled MLS version for '23-'25. Evo has the 3.625" x .030", and Shovelhead the 3.8125" x .040".

Covers and small parts. Cover gaskets run across the catalog: the M8 cam cover, the M8 Touring primary cover, the upper rocker box cover and the M8 transmission lid. O-rings are sold in sets, such as the 10-pack for '17-'24, next to the Evo oil pump body gasket.

Dirt bikes, street bikes and ATVs

About 300 titles say Top End, listed by bore in millimeters and the make. Around 95 carry EST in the part number. Examples include the 102 mm Honda kit, the 96 mm kit for the '09-'14 CRF450R, the 100 mm Yamaha kit, the 82 mm Suzuki kit and the 48.5 mm Kawasaki kit. The Gas Gas/Husqvarna/KTM kit covers that group.

About 15 titles are bottom end kits with oil seals, such as the Honda kit and the Yamaha kit. Single pieces include clutch gaskets, like the Honda and Kawasaki/Arctic Cat ones, stator cover gaskets in Stator & Magneto Parts, the Honda valve cover gasket and exhaust gaskets in Exhaust Gaskets & Seals.

Side-by-side and ATV owners can look at the 93.5 mm Polaris EST kit, the 94 mm Polaris kit and the TRX450R top end kit for '04-'05.

Reading a Cometic title

Each title opens with the Cometic part number, then the part, the bore or thickness, and the model or years. Bore sizes appear in inches on Harley listings and in millimeters on most Japanese and European bike kits, so compare them with your cylinder. Where a title names only a brand, open the listing to check the models.

Cometic questions

How do I pick the right head gasket? Match the engine, years, bore and thickness in the title. The Twin Cam and M8 lists include more than one bore and thickness for the same engine, so read the full title.

Are top end and bottom end kits the same? No. Top end kits and bottom end kits with oil seals are separate listings.

Does Cometic cover older Harleys? Yes, there are listings for Panhead, Shovelhead, Evo and early Sportster engines.

Related guides

!