Mikuni Bs26 Carburetor Manual Verified Repack
Mikuni BS26 Carburetor: The Ultimate Maintenance & Tuning Manual
What of vehicle is this carburetor installed on?
Sits inside the slide, tapering down into the main jet emulsion tube. The Carburetor Body Air Pilot Screw: Controls the idle fuel-air mixture.
Incorrect float height alters the fuel level in the bowl, causing the engine to run consistently rich or lean across the entire RPM range. mikuni bs26 carburetor manual verified
The large brass hex or round jet located in the center of the bowl. Controls full-throttle fueling (3/4 to wide-open throttle).
Rises with the fuel level to shut off incoming fuel via the needle valve seat.
Whether you’re nursing a classic Suzuki Intruder 125 back to life, chasing a stubborn flat spot on a Kawasaki Ninja 150R, or perfecting the idle on an Aprilia Leonardo 125, the is likely at the heart of your fuel system. This isn’t just a part; it’s a finely tuned instrument. Its vacuum-operated slide system offers smooth throttle response, but it also means that when things go wrong, the fix isn't always obvious. This guide cuts through the guesswork and provides the verified technical knowledge and manual-based procedures you need to service the Mikuni BS26 correctly. Mikuni BS26 Carburetor: The Ultimate Maintenance & Tuning
This design prevents the engine from bogging down if you snap the throttle open quickly at low RPM. Complete Specifications Factory Standard Specification Main Jet #110 to #132.5 (Application dependent) Pilot Jet (Idle) #15 to #22.5 Pilot Screw 1.5 to 2.5 turns out from lightly seated Float Height 17.0 mm ± 1.0 mm Step-by-Step Disassembly
Incorrect float height causes fuel overflow or lean starvation.
Before making modifications, establish your baseline. While exact jetting varies by vehicle manufacturer (such as Yamaha, Suzuki, or Kawasaki), the standard Mikuni BS26 baseline configurations are detailed below. Standard Factory Specification Main Jet (Large Round) #110 to #132.5 (Application dependent) Pilot Jet (Idle Jet) #15 to #22.5 Needle Jet P-0 or P-2 Series Jet Needle 4D13 or 5E26 Float Height 21.4 mm ± 1.0 mm (Measured from gasket surface) Pilot Screw (Fuel Screw) 1.5 to 2.5 turns out from lightly seated How the Mikuni BS26 Works Incorrect float height alters the fuel level in
The viton-tipped valve that stops fuel flow when the bowl is full.
Locate the brass pin holding the float hinge. Slide the pin out to release the float assembly and the attached float needle valve. Unscrew the main jet from the center emulsion tube. Unscrew the pilot jet, which sits recessed inside a narrow tunnel. 4. Pilot Screw Removal
Ensure the alignment tab on the outer lip of the rubber diaphragm fits perfectly into the corresponding recess on the carburetor body. If the diaphragm is swollen, let it sit in the sun for an hour to shrink back to its original size. 6. Tuning and Adjusting the BS26