YJGZSVK Carburetor Rebuild Kit for Mikuni HSR 42/45/48mm – Float, Seals & Jets for Harley Twin Cam/EVO

YJGZSVK Carburetor Rebuild Kit supplies the replacement float, seals, jets, and gaskets needed to restore Mikuni HSR 42/45/48 smoothbore carburetors on Harley Twin Cam and EVO Big Twin models.

If your Mikuni HSR smoothbore carburetor is leaking, running rich, or showing inconsistent idle, a rebuild kit replaces the wear items that cause those issues. This kit is built to fit HSR 42mm, 45mm, and 48mm Mikuni smoothbore carburetors commonly installed on Harley-Davidson Twin Cam (1999–2006) and EVO Big Twin (1990–1999) engines. The parts arrive packaged together and intended for a single-carburetor service job.

What parts are included and how do they help?

The kit contains the float, gaskets, O-rings, needle and seat, and other small service components that commonly fail with age. Replacing these items prevents fuel leaks, improves float level control, and restores predictable throttle response.

• Float to maintain correct fuel level in the bowl
• Needle and seat to stop overflow and regulate fuel flow
• Gaskets and O-rings to seal mating surfaces and eliminate vacuum/fuel leaks
• Assorted small hardware for a complete rebuild without scavenging old parts

Will this kit fit my Harley and Mikuni carburetor size?

This rebuild kit is designed specifically for Mikuni HSR smoothbore carburetors in 42mm, 45mm, and 48mm sizes and for the listed Harley models. Verify your carb model marking and physical dimensions to ensure compatibility.

• Fit: Mikuni HSR 42/45/48 smoothbore carburetors
• Harley fitment: Twin Cam (1999–2006) and EVO Big Twin (1990–1999)
• Confirm by matching part shape and float bowl layout
• Contact seller within 24 hours if unsure before purchasing

How difficult is the installation and what tools are required?

Rebuilding a carburetor is a moderate DIY task if you have basic mechanical skills and the right tools. Expect to disassemble the bowl, clean passages, replace the supplied parts, and reassemble while observing torque and clearance specifications.

• Typical tools: screwdrivers, small sockets, pliers, carb cleaning brush
• Use carburetor-safe cleaner to remove varnish and deposits
• Inspect jets and passages visually and blow out with compressed air
• Follow service manual float height and reassembly steps

What should I check after rebuilding the carburetor?

After reassembly, verify there are no fuel leaks, the float operates freely, and the engine runs smoothly through idle to full throttle. Fine-tune mixture and idle settings as required and recheck for stable operation during a short test ride.

• Confirm no fuel leaks at the bowl seams or overflow
• Set and verify float height per Mikuni specs
• Adjust idle and mixture screws for smooth throttle transition
• Test under various loads to ensure consistent performance

Who is this for: The YJGZSVK carburetor rebuild kit is intended for motorcycle owners, mechanics, and restoration enthusiasts working on Mikuni HSR smoothbore carburetors fitted to Harley Twin Cam and EVO Big Twin machines. It’s aimed at anyone who wants to replace worn internal carburetor parts to stop leaks and restore reliable fuel metering without buying a new carburetor. If you lack experience with carburetor service, consider having a professional perform the rebuild to ensure correct settings and safe operation.