If you are storing your snowmobile or ATV for the season, the BDS26 service manual includes a storage protocol:
You will find third-party manuals (e.g., Clymer, Haynes) that cover multiple carburetors including the BDS26. These are acceptable for general procedures but often lack specific data like:
For critical adjustments, track down the Mikuni Factory Service Manual or the OEM vehicle service manual (e.g., 1992 Arctic Cat Prowler manual). The part number you need is often Mikuni BDS26-1.
Tools Required:
Step-by-Step Disassembly:
Top End Disassembly (Diaphragm Assembly):
Float Bowl Disassembly:
Float and Valve Removal:
Jet Removal:
Pilot Screw Removal:
If your engine uses two BDS26 carbs (common in twin-cylinder snowmobiles), the service manual includes a synchronization procedure using a manometer or a drill bit method. The goal: both slides begin to move at exactly the same throttle opening (typically 0.5mm gap at idle).
Before starting, confirm you have a BDS26. It is a Diaphragm-type carburetor (constant velocity/vacuum), usually 26mm in diameter.