How do you adjust the carburetor on a 40 HP Mercury 2 stroke outboard?

Turn the idle speed screw on the carburetor linkage to adjust the motor’s speed to between 700 and 800 rpm. Put the motor in “Forward.” Turn the mixture screw clockwise until the motor begins to misfire. Turn the screw counterclockwise one-quarter turn or until the motor no longer misfires.

How do you adjust a 2 stroke carb outboard?

How to Adjust a 2-Cycle Outboard Carburetor

  1. Take the cover off the 2-cycle outboard motor, and start the engine, letting it warm up for a few minutes.
  2. Locate the stop screw knob on the left side of the motor, and turn the knob counterclockwise to slow the engine down or clockwise to speed up the engine.

How do you adjust the idle on a 40 hp Mercury outboard?

Insert a screwdriver into the Mercury’s idle adjustment screw, located at the bottom of the carburetor, and turn it to the left until the motor barely continues to run. Insert the screwdriver into the valve screw and turn it in 1/8-turn increments to the right until the motor idles evenly and smooth.

How do you adjust the air screws on a carburetor?

Turn the screw clockwise until the engine starts to sound rough.

  1. Tightening the screw weakens the air and fuel mixture and decreases the amount of fuel flowing to the engine.
  2. Tightening the screw is also called making the fuel mixture leaner, which lowers the RPMs at which the engine idles.

Why is my 2 stroke outboard sputtering?

In reality, this problem can be caused by a variety of issues. Everything from fouled or corroded spark plug wires to debris in the gas can cause sputtering or loss of power.

How do you adjust idle on Force 40 hp?

Why does my boat stall in idle?

If your outboard stalls whenever you drop it into idle, the problem usually lies with the carburetor. It might be something as simple as the carburetor idling screw needing a small adjustment, so check that first and adjust it if needed.