This verified manual provides factory specifications, step-by-step rebuilding procedures, troubleshooting charts, and tuning insights to keep your engine running perfectly. Technical Specifications & Factory Jetting
Submerge all brass pieces in commercial carburetor cleaner or an ultrasonic cleaner solution for 20 minutes.
Use a dip basket or specialized cleaner for stubborn varnish, but always remove rubber gaskets and O-rings first to prevent swelling. Blow out all orifices with compressed air after soaking.
Q: How do I adjust the idle mixture on my Mikuni BS26 carburetor? A: Turn the pilot screw counterclockwise to richen the mixture or clockwise to lean the mixture. mikuni bs26 carburetor manual verified
Mikuni BS26 Carburetor Manual: Verified Tuning, Rebuild, and Operation Guide
in the choke cable. Lack of slack can cause the plunger to stay partially open, leading to a rich mixture and poor idling. Common Troubleshooting BS Carburetors - Mikuni Power
| Circuit | Typical BS26 range | GS500 (1996–2000) | |---------|-------------------|--------------------| | Pilot jet | 35 – 45 | 37.5 | | Main jet | 120 – 140 | 125 | | Pilot air jet | 80 – 120 | 95 | | Needle clip position | Groove 1–5 | 3rd from top | Blow out all orifices with compressed air after soaking
Required to accurately measure and set the float height to factory specifications. Step-by-Step Teardown Highlights: Preparation:
The Mikuni BS26 is a constant velocity (CV) carburetor widely used in small-displacement motorcycles, ATVs, and scooters. Renowned for its smooth throttle response and fuel efficiency, this carburetor relies on engine vacuum to operate its slide.
Essential for preventing overflow or fuel starvation. Measurement is typically taken from the gasket surface to the highest point of the float. Mikuni BS26 Carburetor Manual: Verified Tuning, Rebuild, and
The Mikuni BS26 is a Constant Velocity (CV) side-draft carburetor that has been a staple in small-to-medium displacement four-stroke motorcycles, particularly popular on vintage Suzuki, Yamaha, and Kawasaki models, as well as various modern, smaller-displacement machines. Its design focuses on smooth power delivery and fuel efficiency through a diaphragm-operated slide.
Remove the screws securing the top vacuum cover. Carefully extract the soft spring and lift out the rubber diaphragm and throttle slide assembly. Inspect the diaphragm for pinholes, tears, or hardening.
The BS26 operates on a variable venturi design where a vacuum-operated diaphragm controls the slide lift, ensuring smooth throttle response across various engine speeds. Most tuning issues originate in one of five metering systems:
The garage door was open to the cool evening air. Elias thumbed the starter. The engine turned—once, twice—and then settled into a steady, rhythmic purr. No more sputtering. No more hesitation.
The Mikuni BS26 relies on three primary fuel circuits to deliver the correct air-fuel mixture across the entire throttle range.