Mikuni Bs26 Carburetor Manual Verified -
The information provided in this article has been verified through the following sources:
The specific of your vehicle for exact jetting numbers.
Remove the float bowl and top vacuum cap. Be careful not to tear the rubber diaphragm attached to the slide.
The information provided in this manual is for general information purposes only. Always consult the manufacturer's instructions and specifications for specific details and guidelines. We are not responsible for any damage or injury caused by incorrect use or modification of the Mikuni BS26 carburetor. mikuni bs26 carburetor manual verified
The Mikuni BS26 carburetor is a popular and highly-regarded carburetor used on a variety of motorcycles, scooters, and other small engines. Known for its reliability and performance, the BS26 has become a favorite among enthusiasts and mechanics alike. In this article, we'll provide a comprehensive manual for the Mikuni BS26 carburetor, including specifications, troubleshooting tips, and maintenance procedures.
Last verified against factory service manuals: Suzuki GSX250 (1991), Kawasaki ZZR250 (1996), Bajaj Pulsar 220 DTS-i (2010).
Gently turn the pilot screw clockwise until it lightly seats. Do not overtighten, or you will snap the tip. Back the screw out as a baseline. The information provided in this article has been
The Mikuni BS26 is a sophisticated CV carburetor that, when understood through the lens of factory service data, offers reliable fueling and smooth power delivery. Its diaphragm-actuated slide, adjustable pilot air circuit, and precise float height settings are critical to proper function. Owners and technicians who follow verified procedures—especially the 30° float height check and correct interpretation of the air screw—will avoid the tuning pitfalls common to online forums. For any significant deviation from stock (exhaust, intake), the BS26 responds well to main jet changes (#125–#135) and needle shimming, but only within the limits of its CV design. When in doubt, the factory manual remains the definitive source.
Spray the exterior with aerosol carburetor cleaner to prevent dirt from entering the internal circuits during disassembly. Step 2: Diaphragm Inspection (Top Section)
Controls operation from 3/4 to wide-open throttle (WOT). At this point, the needle is lifted fully out of the jet, and fuel flow is restricted solely by the size of the main jet. Step-by-Step Rebuild Guide The information provided in this manual is for
| Fastener | Verified Torque (in-lbs) | Warning | | :--- | :--- | :--- | | Float Bowl screws | 7-9 in-lbs | Use a JIS screwdriver, not Phillips. | | Top cap screws (diaphragm cover) | 4-6 in-lbs | Overtightening distorts the diaphragm sealing surface. | | Drain plug (bottom of bowl) | 13 in-lbs | Replace the copper crush washer every time. | | Choke plunger nut | Hand tight + 1/8 turn | Plastic threads—do not use tools. |
Note: If the screw requires more than 3 turns to reach peak idle, the pilot jet is likely too large; if less than 1.5 turns, the pilot jet may be too small.
The Mikuni BS26 is a 26mm Constant Velocity carburetor utilizing a vacuum-operated diaphragm, commonly tuned with a pilot screw set 1.5 to 2 turns out. Key maintenance involves cleaning the jet circuits, checking for varnished fuel, and ensuring the float needle seats properly. For detailed schematics, view the Mikuni BS26 Manual on Scribd
: Following the manual’s baseline setting , he seated the mixture screw lightly and backed it out exactly 1.75 turns. The First Start