Japanese Industrial Standard tips prevent stripping Mikuni screws.
Spray all passages and jets with carburetor cleaner. Use compressed air to blow out passages. Do not use wire in the jets as this can damage the orifices.
The official BDS26 service information is contained within the for the specific motorcycle. Here’s how to find it:
Use a dedicated carburetor cleaner or an ultrasonic bath. Avoid using wire to clean jets, as it can enlarge the precision-drilled holes; use compressed air instead. Reassembly Tips: rubber conditioner Rubber RnR fluid ) on diaphragms to maintain flexibility. Apply a small amount of anti-seize paste to bowl screws to prevent future stripping. LiteTek.co 3. Tuning and Adjustments
Spray aerosol carb cleaner through every single orifice. Ensure fluid exits cleanly from the corresponding exit holes inside the bore. Mechanical Orifice Clearing mikuni bds26 service manual
Before altering your carburetor, establish your baseline factory specifications. 26mm
Cause: Debris stuck in the needle valve, a worn rubber needle tip, or a heavy, fuel-logged float. Cause: Clogged pilot jet or a leaking vacuum diaphragm.
Start the engine and adjust the synchronization screws between the carb bodies until all vacuum readings are equal.
Once mounted back onto the engine, perform these final steps to optimize performance. Synch and Idle Adjustment Do not use wire in the jets as this can damage the orifices
These are example values – refer to your specific manual for your engine model.
The Mikuni BDS26 is a 26mm downdraft, constant velocity (CV) carburetor commonly found on multi-cylinder motorcycles like the Yamaha Seca II and the Hyosung GV250. Unlike standard slide carburetors, the BDS26 uses a vacuum-operated diaphragm to control the throttle slide, ensuring smoother throttle response and better fuel atomization across various RPM ranges.
When you run into more specific problems, the enthusiast community has solutions for nearly everything, such as how to drill out stripped butterfly valve screws to change the shaft seals or where to find a replacement jet needle if the tip is broken.
: These smaller cruisers typically use a single carburetor. Avoid using wire to clean jets, as it
Flip the carbs over and remove the four screws holding the float bowls. If they are stuck, a light tap with a plastic mallet can help.
If you have landed on this page, you are likely staring at a vintage carburetor with “Mikuni BDS26” stamped on the side. Whether it is bolted to a classic Arctic Cat snowmobile, a vintage Yamaha Enticer, or a custom go-kart, one truth remains universal:
JIS (Japanese Industrial Standard) Screwdrivers (Avoid standard Phillips to prevent stripping screws) Metric Socket Set Needle-nose pliers Carburetor cleaner spray Compressed air