Mikuni Bds26 Service Manual (2026)

With the carburetor upside down, measure the distance from the gasket surface to the float. Adjust the tang on the float to match factory specifications.

Secures the pull/push throttle cables.

For an in-depth, specific rebuild, refer to the Mikuni PHH Service Manual for general principles and specialized Mikuni Resources for jetting information.

Install the spring, place the top cap back over the assembly, and torque the screws evenly. Troubleshooting and Synchronization Diagnostics mikuni bds26 service manual

Before beginning the teardown, familiarize yourself with the internal architecture of the Mikuni BDS26. Standard Factory Specifications (Yamaha XV250 Reference)

Once reinstalled on the engine, the Mikuni BDS26 requires fine-tuning under operating temperatures. Diagnostic Matrix Probable Cause Corrective Action Stuck float or worn needle valve seat O-ring Clean float chamber, replace float needle valve. Engine hangs at high idle Hanging slide or vacuum leak at boot intake Check diaphragm seating; check intake boots for cracks. Backfiring through intake Lean pilot circuit mixture Back out the pilot mixture screw 1/4 turn at a time. Bogs down under load Clogged main jet or torn vacuum diaphragm Clear main jet with compressed air; replace diaphragm. Idle Mixture Optimization

This guide provides technical specifications, maintenance procedures, and tuning steps for the Mikuni BDS26. With the carburetor upside down, measure the distance

Once the Mikuni BDS26 is reinstalled on the engine, you may need to perform fine-tuning adjustments. Probable Cause Corrective Action Lean pilot circuit / Torn coasting enricher diaphragm Check enricher valve; turn pilot screw out 1/4 turn. Engine bogs at 4,000+ RPM Torn vacuum slide diaphragm / Clogged main jet Inspect slide action; clear main jet passage. Fuel leaks from overflow tubes

Spray aerosol carburetor cleaner through every passage, passage mouth, and jet. Ensure fluid exits cleanly from the corresponding exit hole.

For critical adjustments, track down the or the OEM vehicle service manual (e.g., 1992 Arctic Cat Prowler manual). The part number you need is often Mikuni BDS26-1 . For an in-depth, specific rebuild, refer to the

Loosen clamp screws, disconnect throttle cables, choke cable, and fuel hoses. Remove the carburetor unit.

[Carb Body] ──> Spray Carb Cleaner ──> Compressed Air ──> Clear Passages │ If still clogged ────────┴──> Ultrasonic Bath

Once mounted back onto the engine, perform these final steps to optimize performance. Synch and Idle Adjustment

2.0 turns out from lightly seated Key Components to Locate

Hold the carburetor body at a 45-to-60 degree angle so the float tang rests lightly against the needle plunger without compressing the internal spring.