STIHL MS 261, MS 261 C Chainsaw Service Manual (P/N 1141-792-9101)

• Covers the 2010 STIHL MS 261 and MS 261 C chainsaws and the 1994-1997 Suzuki RF900R motorcycles, outlining diagnostic and service procedures for both standard and specialty variants.
• Official OEM publication (© 2010 ANDREAS STIHL AG & Co. KG, revision May 2010, part number 1141-792-9101 and Suzuki part number 99500-39123-03E) spanning 335 pages (with over 450 pages of supplementary data for the motorcycle platform).
• Contains 125 technical illustrations, over 35 exploded-view assembly diagrams, and 3 comprehensive diagnostic flow charts for ignition and lubrication systems. Covers fuser assembly, paper path, and imaging procedures, plus diagnostic flowcharts.
• Incorporates critical visual aids including wiring diagrams, vacuum hose routing diagrams, tappet shim selection tables, periodic maintenance charts, electrical schematics, compression pressure charts, and camshaft positioning views.
• Detailed torque-specification table provides precise values for over 50 assembly points across the engine and chassis.
• Accessing this PDF directly at the workbench provides exact factory tolerances, eliminating trial-and-error and significantly accelerating your component rebuilds for a safe, professional repair.
• Documents the specific diagnostic requirements for the professional-grade 50.2 cc engine platform, the 937 cm3 engine platform, and the integration of QuickStop Super braking systems.
• Explains the systematic teardown of the Suzuki RF900R, Mikuni BDST36 carburetors, water-cooled DOHC TSCC systems, 5-speed constant mesh transmissions, telescopic front forks, link type rear suspensions, starter idle gears, and dual disc brakes.
• Features detailed instructions for tappet clearance adjustments, hydraulic brake bleeding, clutch fluid replacement, drive chain alignment, coolant system flushes, compression pressure testing, oil pump inspections, camshaft timing, and main bearing selection.

System Coverage and Sub-Assemblies

This factory publication details the critical specifications required to understand and service the STIHL MS 261 power unit and the Suzuki RF900R powertrain. Coverage spans the engine cylinder and crankshaft, clutch and brake systems, fuel supply, carburetor setup, and the rewind starter mechanism. It segments the equipment into manageable logical sections, documenting the exact layout and assembly order for components like the handlebar, AV system, control levers, and the dedicated heating system found on specialized models. The manual also highlights the required proprietary service tools, including the 5910 890 3101 assembly stand, the 09920-53740 clutch sleeve hub holder, and various bearing installation sleeves. By providing these step-by-step instructions for tasks like balancing carburetors, overhauling telescopic forks, and setting strict valve clearances, the guide enables technicians to handle complex maintenance in-house, avoiding expensive dealership labor rates for a major repair.

Technical Specifications and Calibration

Expect precise factory data on engine performance parameters, ignition timing, and lubrication system flow rates. Before starting any diagnostic teardown, always ensure the power unit is fully depressurized, the spark plug and negative battery cable disconnected, and the chain brake engaged to prevent accidental injury or chemical exposure.

The factory engine idle speed is set at 2,800 rpm for the chainsaw and 1,200 rpm for the motorcycle. You will find the ignition module air gap specified at 0.20 mm (+ 0.1/- 0.05 mm) and the cold intake tappet clearance at 0.10-0.20 mm within the data tables. Lubrication system oil pump flow is documented at 11.5 cm³/min at 10,000 rpm on the maximum setting, while the motorcycle's oil pressure is rated above 300 kPa at 3,000 rpm. The guide lists all mandatory tightening torques, such as the strict 50 Nm specification for the carrier-to-crankshaft connection and the 150 N-m limit for the clutch sleeve hub nut, ensuring professional-grade accuracy during reassembly.