Stihl HS 87 R Product Instruction Manual - Page 20

443BA044 KN English Engine Management Adjusting the Carburetor Standard Setting Exhaust emissions are controlled by the design of the fundamental engine parameters and components (e.g. carburation, ignition, timing and valve or port timing) without the addition of any major hardware. General Information The carburetor comes from the factory with a standard setting. This setting provides an optimum fuel-air mixture under most operating conditions. Preparations N Shut off the engine. N Check the air filter and clean or replace if necessary. N Check the spark arresting screen in the muffler and clean or replace if necessary. N Inspect cutting blades and clean if necessary (clean, move freely, not warped). N Turn high speed screw (H) counterclockwise as far as stop (no more than 3/4 turn). N Turn the low speed screw (L) clockwise as far as stop, then turn it back 3/4 turn. Adjusting Idle Speed N Carry out the standard setting. N Start and warm up the engine. 443BA045 KN Engine stops while idling N Turn the idle speed screw (LA) clockwise until the cutting blades begin to run - then back it off 1 1/2 turns. 18 HS 87 R, HS 87 T