Stihl MS 461 Rescue Instruction Manual - Page 11

1 2 N Turn the cap (with the grip up) until it drops into the fuel tank opening. N Next, turn the cap counterclockwise as far as it will go (approximately 1/4 turn). This will rotate the base of the cap into the correct starting position for installation. The exterior positioning mark (1) on the cap will line up with the "unlocked" symbol (2) on the fuel tank housing. N Then, turn the cap clockwise, closing it normally. If your fuel cap still does not tighten properly, it may be damaged or broken. Stop using the unit and take it to your authorized STIHL dealer for repair. Vapor Lock WARNING Vapor lock occurs when fuel in the fuel line or carburetor vaporizes, causing bubbles to block the free flow of liquid fuel into the carburetor. Vapor lock cannot be relieved or affected by opening the fuel tank. Removing the fuel filler cap without first allowing the chain saw to cool adequately can result in fuel spraying. Always follow the instructions in this section when removing the fuel cap. 0000-GXX-6422-A0 To relieve vapor lock: - Place the Master Control Lever in the cold start position l and pull the starter cord approximately 20 times to clear the vapor and send liquid fuel into the carburetor. - To start the chain saw, move the Master Control Lever to the starting throttle position n and pull the starter cord approximately 10 times. - If your chain saw will not restart, or if vapor lock occurs again, the chain saw is being used in conditions too extreme for the fuel being used. Discontinue use and let the engine cool completely before attempting to start the chain saw. - Using good quality, fresh fuel (stored less than 30 days) also can help reduce the occurrence of vapor lock. Pick the Right Fuel Using good quality, fresh fuel (stored less than 30 days) also can help reduce the occurrence of vapor lock. Before Operation Take off the chain guard (scabbard) and inspect the chain saw for proper condition and operation. (See the maintenance chart near the end of the instruction manual.) WARNING Always check your chain saw for proper condition and operation before starting, particularly the throttle trigger, throttle trigger lockout, stop switch and cutting attachment. The throttle trigger must move freely and always spring back to English the idle position. The Master Control Lever / stop switch must move easily to STOP, 0 or †. Never attempt to modify the controls or safety devices. WARNING Check fuel system for leaks, especially the visible parts, e.g., filler cap, hose connections, manual fuel pump (only for chain saws equipped with a manual fuel pump). Do not start the engine if there are leaks or damage - risk of fire. Have the chain saw repaired by a STIHL servicing dealer before using it. WARNING Check that the spark plug boot is securely mounted on the spark plug - a loose boot may cause arcing that could ignite combustible fumes and cause a fire. For proper assembly of the bar and saw chain follow the procedure described in the chapter "Mounting the Bar and Chain" of your instruction manual. STIHL Oilomatic saw chain, guide bar and sprocket must match each other in gauge and pitch. Before replacing any bar and chain, see the chapter entitled "Specifications" in the instruction manual and the chapter "Reactive Forces including Kickback". Since longer bars add weight and may be more difficult to control, select the shortest bar that will meet your cutting needs. WARNING Proper tension of the chain is extremely important. In order to avoid improper setting, the tensioning procedure must MS 461 R 9