TC Bros. Breather Bolts for Harley-Davidson Sportster 1991-2022 and Ev

Harley-Davidson aftermarket carburetor filter kit with TC Bros Breather Bolts For 1991-2022 Sportster & EVO Big Twin for improved crankcase venting.

A pair of TC Bros Breather Bolts for 1991-2022 Sportster & EVO Big Twin bolts on a white background.

TC Bros. aftermarket breather bolts on a white background.

A pair of TC Bros Breather Bolts For 1991-2022 Sportster & EVO Big Twin with aftermarket air cleaners on a white background.

A pair of TC Bros Breather Bolts For 1991-2022 Sportster & EVO Big Twin - Black on a white background.

Two TC Bros breather bolts and washers on a white background.

A TC Bros red box full of metal nuts and bolts in a factory, used for crankcase venting.

TC Bros. TC Bros Air Cleaner/Carb Support Bracket aftermarket air filters for a Harley-Davidson motorcycle air cleaner.

A close up of a TC Bros. Finned Raw Air Cleaner HD CV Carbs & EFI vintage style motorcycle with a red and black engine.

A diagram illustrating the parts for the TC Bros Breather Bolts For 1991-2022 Sportster & EVO Big Twin, including aftermarket air cleaners and crankcase venting.

$44.95

Color — Raw Machined

Raw Machined

Black

In stock
Inventory on the way

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TC Bros. Breather Bolts for Harley-Davidson Sportster 1991-2022 and Evo Big Twin 1993-1999

Stock airboxes on late Evolution-powered Sportsters and Big Twins integrate a provision for crankcase breathing through the cylinder heads. Eliminating the airbox to run an aftermarket air cleaner also eliminates the hollow breathing bolts.

Fits Evo with head breather (Sportster 1991-2022, Big Twin 1993-1999 exc. Twin Cam)
Available in Raw Machined or Black finish
Permits use of many aftermarket air cleaners (including all TC Bros. units)
Air cleaner support brackets available separately; required for most aftermarket air cleaner installations
Made in USA
CNC-machined from 6061 aluminum

These bolts offer an unobtrusive, alternative crankcase venting option when installing aftermarket air cleaners on your Harley-Davidson. They are CNC-machined from 6061 aluminum and offered in two attractive finishes. Stainless steel vent screens, stainless washers, circlips and foam filter elements are included. Sidestep ugly hoses and bulky breather filters with a set of TC Bros. Breather Bolts. Not legal for sale or use in California.

1991-2022 Harley-Davidson Sportster
1993-1999 Harley-Davidson Big Twin exc. Twin Cam
Some 1992 cylinder heads may appear to be top-breathing engines but machining is not complete from the factory; please verify that your engine is not a bottom-breather before ordering