Controls idle and low-end throttle (up to ~1/4 turn). The air screw should typically be set between 1.5 and 1.75 turns out Needle & Jet: Manages the mid-range (1/4 to 3/4 throttle). Takes over at wide-open throttle (WOT). Choke System: Operates via a plunger; when the plunger is , the choke is Identifying Genuine Parts

If you own a classic Japanese motorcycle from the late 1980s to the early 2000s—especially a Suzuki GS500, GN250, or DR350—you have almost certainly encountered the carburetor. This "Constant Velocity" (CV) carb is known for its smooth throttle response and fuel efficiency, but it is equally infamous for clogged pilot jets, sticky diaphragms, and vacuum leaks.

| Model | Main Jet | Pilot Jet | Air Jet | Float Height | |-------|----------|-----------|---------|---------------| | GS500 (89-00) | 127.5 | 37.5 | 120 | 14.6mm | | GN250 | 102.5 | 35 | 90 | 17.0mm | | DR350 (kick) | 135 | 42.5 | - | 13.0mm |

Need a printable PDF version of this manual? Search for "Mikuni BS26 manual PDF" plus your specific motorcycle model (e.g., "Suzuki GS500") for official torque specs and vacuum routing diagrams.

If you need a specific section (exploded diagram, jetting chart, or rebuild steps), let me know and I can extract or reformat it for you.