Lowbrow Customs Breather Bolts for Harley-Davidson Motorcycles
What are breather bolts? Breather bolts are a necessary component when running a custom air cleaner on your Harley-Davidson Evolution or Twin Cam motorcycle. Stock air cleaners typically have a support bracket integrated, which supports the carburetor and intake manifold and keeps the carburetor from rotating downward from bumps and vibration. Stock motorcycles also direct the air from the engine breathers into the intake tract of the carburetor. Harley-Davidsons with custom air cleaners need a separate carburetor support bracket and a set of custom breather bolts, simplifying and streamlining the entire air cleaner assembly. This typically allows for a smaller air cleaner and allows all sorts of customization to make the motorcycle look much different than stock. There are two different size threads used depending on what engine is in the motorcycle. For Evolution Big Twin and Sportster engines it is a 1/2"-13 thread, and for Twin Cam it is 3/8"-16.