How do you service a 2 stroke outboard motor? How to service a 2-stroke outboard engine Do it yourself! This step-by-step guide takes you through a service of a small 2-stroke outboard. 1: Drain the old fuel. Check the spark plug. Check the recoil starter. Remove, strip and clean the carburettor. The lower leg. Remove the gearbox to check the water pump. On smaller engines with only one gear…
how do you adjust the throttle on an outboard motor?
Throttle Adjustment
How do I adjust the carburetor on my boat? The idle adjustment is on the underside of an outboard carburetor. Use a small adjustable wrench or screwdriver and rotate the idle adjustment 1/4 turn clockwise until the engine idle slows. Rotate the valve counterclockwise in 1/8-turn increments until the engine idles smoothly.
Low speed mixture screw
Move the throttle to the “Idle” position. Move the throttle cable sleeves up or down in the mounting bracket until the cam-follower roller until is centered over the raised mark on the cam, and tighten the cable jam nuts.Tighten the cam-follower screw and turn the idle-speed screw inward until there is a gap of 0.005 inches to 0.04 inches between the cam and the cam follower.
Start the motor and allow it to idle until it reaches its normal operating temperature. Adjust the idle-speed screw so that the idle speed is between 700 and 800 RPM.
Turn the motor off and shift it into “Neutral.” Use a standard screwdriver to loosen the cam-follower screw on the carburetor. Loosen the idle screw, located to the left of the throttle until the throttle plate is closed: the throttle-shutter positioner will not touch the taper of the idle speed screw. Loosen the jam nuts on the throttle-cable sleeves, just below the throttle cam.
Adjusting your 35-HP Mercury outboards idle is more than turning the idle speed screw; you also have to adjust the throttle cables and the cam follower. The extended time required for this process means that a flushing attachment may not supply enough water to avoid engine damage. The 30- to 40-HP Mercury outboards all used some version of the Walbro WME carburetor, not all of which have a mixture-adjustment screw.
Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.
FAQ
How do you adjust the idle on a 2 stroke Mercury outboard?
How do you adjust a Mercury outboard carburetor?
Where is the adjustment for idle screw located?
