Suzuki DF25/DF30 Four Stroke Service Manual, Page 38Get this manual
PERIODIC MAINTENANCE 2-11
IDLE SPEED
Inspect initially after 20 hoursmonthand every 200 hours (12 monthsthereafter
Checking
NOTEBefore checking the idle speed, the engine should be allowed to warm up Check andor adjust the idle speed after the engine speed has stabilized1Check link mechanism and carburetor throttle valves for smooth operation2Connect the tachometer lead wires as follows: 34200-92E02Engine tachometer 34Yellow lead wire to the YellowBlack lead wire of CDI unitGray lead wire to DC 12V power source positive terminalBlack lead wire to DC 12V power source negative terminalSet the pole selection switch in the tachometer to "12"Start the outboard motorCheck the idle speedIdle speed (in neutral gear)850 950 rmin