Mikuni Air Cleaner Adapter

Trask's billet adapter, so an S and S E, G or Keihin CV style air cleaner bolts to a Mikuni HSR carburetor.

The Mikuni HSR 42 and 45 are among the most common carburetor swaps on a Harley-Davidson, and the one thing they do not come with is a way to run the air cleaner you already own. The bolt pattern and the flange on an HSR do not match the S and S E and G series or the Keihin CV, which is what nearly every Harley air cleaner on the market is cut for. Trask machines this adapter from T-6061 billet to bridge the two, so a carburetor change does not force an air cleaner change as well.

Features of the Trask Mikuni Air Cleaner Adapter

• Adapts Mikuni HSR 42 and 45 carburetors to S and S E, G or Keihin CV style air cleaners
• Machined from T-6061 billet aluminum
• Made in the U.S.A.

Mikuni Air Cleaner Adapter Fitment

• Mikuni HSR 42 and HSR 45 carburetors
• Air cleaners cut for S and S E or G series, or Keihin CV mounting

⚠️ VERIFY your air cleaner's mounting pattern before ordering. This adapter goes from the Mikuni to the S and S E and G or Keihin CV pattern, and an air cleaner cut for anything else will not bolt to it.

Common Questions About the Adapter

Will it work with a Stealth air cleaner?
It depends on the backing plate. If the backing plate is cut for the S and S E and G or Keihin CV pattern, yes. Check the backing plate, not the cover.

Does it change how the carburetor breathes?
It is a mounting adapter. It puts the air cleaner where the carburetor is, and it does not restrict the bore.

Is hardware included?
Check what came with your air cleaner. Adapter length can change the bolt length you need, so have the carburetor and the air cleaner side by side before you order fasteners.