Mikuni Bds26 Service Manual ((free)) -

While specific tuning depends on the exact bike model, the "factory" baseline for a Mikuni BDS26 on a standard 250cc cruiser is generally:

Standard sizes range from #87.5 to #90 depending on the cylinder (front/rear). Pilot Jet: Typically #20. mikuni bds26 service manual

Understanding the operation is vital for diagnostics: While specific tuning depends on the exact bike

Typically 2.0 to 2.5 turns out from lightly seated. Main Jet: Standard size is usually a #110 or #112.5. 4. Troubleshooting Common Issues mikuni bds26 service manual

Suggests a clogged main jet or a torn diaphragm preventing the slide from lifting.