How to Adjust Slow Speed on a 6 HP Johnson Outboard

Explore America's Campgrounds

Adjusting the slow speed on a 6 HP Johnson outboard motor regularly will keep the engine running efficiently and provide better fuel economy. The slow-speed idle adjustment screw, also referred to as the low-speed needle, is located near the front of the outboard motor carburetor. The slow-speed idle adjustment screw can be adjusted in just a few minutes with a screwdriver, saving you time and money.

Items you will need

  • Screwdriver

Step 1

Turn the slow-speed idle adjustment screw clockwise with a screwdriver until the screw is seated without over-tightening the screw.

Step 2

Adjust the slow-speed screw by turning it counterclockwise 1 1/2 turns with a screwdriver to find the starting point for further adjustment.

Step 3

Start the outboard motor and let it warm up for about five minutes. Set the throttle at a slow trolling speed.

Step 4

Adjust the slow-speed idle by turning the screw clockwise 1/4 turn at a time until the motor begins to stall; then turn it back counterclockwise 1/4 turn to find the proper setting on the 6 HP motor.

About the Author

Carl Pruit has been a freelance writer since 2005, specializing in service journalism and travel. His work has appeared on various websites. Born and raised in California, Pruit attended Contra Costa Community College in San Pablo, Calif. and received an associate degree in the administration of justice.