How to Rebuild an Outboard Carburetor

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It may leave you smelling of gasoline and hand cleaner, but rebuilding your outboard motor's carburetor properly is likely to increase both its efficiency and performance. Rebuilding the carburetor may be a one-afternoon project, or you may spread the work over several days. It's not a project you have to undertake on any schedule; you do it "as needed," making a project for the off season, during your winter layup or during the spring outfitting.

Remove the air intake silencer from the motor. Disconnect the drain hose from the nipple at the bottom of the silencer. Unsnap the choke link from the carburetor choke lever. Unsnap the throttle linkage from the throttle arm.

Remove the carburetor mounting screws with a Torx driver. Remove the carburetor and gasket from the intake manifold. Position a rag or small drain basin to catch any fuel left in the line, and disconnect the line's quick-connect from the carburetor. Remove the carburetor completely from the motor.

Unscrew the low speed needle and remove the pilot jet mounted in the top of the carburetor. Remove the air jets from the cast pockets in the front opening of the carburetor throat using a small screwdriver, and tag the air jets with prewired paper tags identifying their places in the carburetor, since installing them in the wrong location can lead to significant engine performance problems.

Hold the carburetor over a small drain basin and remove the float bowl drain screw from the bottom of the carburetor with a screwdriver. Turn the carburetor upside down and drain the bowl. Discard the screw gasket. Remove the float bowl and gasket from the underside of the carburetor body.

Remove the hinge pin and take out the float and valve. Remove the main jet and nozzle from the carburetor body.

Set the metal carburetor parts in a colander, just like the ones you find in the kitchen, and dipping them in carburetor cleaner. When they are clean, allow them to air dry. Replace any parts that require replacement with those from the carburetor kit.

Install the main jet and nozzle and hold the float in place just tightly enough to install the hinge pin. Measure how far the float moves using both the template in the carburetor kit and a machinist's ruler according to the directions in the carburetor kit.

Install the float bowl before turning the carburetor right-side-up. Remove the tags from the air jets as you install them according to the location information on their respective tags, pushing them into place with the small screwdriver. Apply thread locker to the carburetor mounting screws.

Hold the carburetor in one hand while connecting the the fuel supply line quick-connect connector onto the fuel inlet with the other. Install the carburetor gasket without using gasket sealant. Insert the mounting screws through the carburetor's mounting flange and place the new gasket from the carburetor kit over the bolts and set the carburetor in place on the intake manifold. Tighten the screws to 72 inch-pounds with a torque driver and Torx bit.


  • "Evinrude Repair Manual -- 2.5 to 250 HP Models, 2002-2007"; Seloc Marine; 2007

About the Author

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.

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  • toy outboard motor image by pearlguy from Fotolia.com