The manual specifies a (measured with the carb upside down, gasket removed, and float tang just touching the needle spring). Novices set the float parallel to the bowl – that is wrong. The BDS26 is extremely sensitive to fuel height. A 2mm error will cause flooding or a lean stumble.
Before turning a single screw, it is vital to understand the architecture of the BDS26. Unlike the round-slide VM series, the BDS series features a "flat-slide" or "constant velocity" (CV) style design in a compact form factor. The "26" denotes a 26mm venturi diameter, making it perfect for 125cc to 200cc engines. mikuni bds26 service manual
Standard factory settings for the BDS26 can vary by model, but for most applications like the Hyosung GV250, use the following: 26 mm Main Jet (M.J.): #90 (Front), #87.5 (Rear) Pilot Jet (P.J.): #20 Idle RPM: 1,450 – 1,550 RPM Float Height: 17 mm (± 1.0 mm) 2. Disassembly & Cleaning The manual specifies a (measured with the carb
: #90 (Front), #87.5 (Rear) — Note: jets often differ between cylinders for heat management Pilot Jet : #20 Needle Jet : O-6 Service & Disassembly Procedures A 2mm error will cause flooding or a lean stumble