Johnson Carburetor Cleaning (1hp to 40 hp) 1989-2005

A carburetor is a device attached to Johnson outboard internal combustion motor and it’s designed to mix air with a fine spray of gasoline. On occasions, a Johnson outboard carburetor will get dirty and need to be cleaned to make it free of dirt, marks or messes.

Cleaning a Johnson carburetor involves removing it from the engine, disassembling it, and cleansing it or wiping it free of grime using a cloth, compressed air or with a brush. This guide describes the process of how to clean a Johnson outboard carburetor.

Carburetor Cleaning


The carburetor must be removed from the engine and disassembled before it can be cleaned. Once disassembled, use a clean bristle brush to remove varnish deposits, dirt and grime. Use Carburetor and Choke Cleaner to wash all components clean.

IMPORTANT: Never submerge Johnson outboard carburetor or it’s components in a hot soaking tank or submerged in a strong carburetor cleaner. Strong carb cleaners have a tendency to remove critical sealing compounds and can even damage components.

Use a small syringe filled with isopropyl alcohol to to flush carburetor passages and holes. Use compressed air to blow the carburetor and its passages dry. The compressed air should not reach more than 25 psi (172 kPa). When using the compresses air to dry passages, make sure the air flow is traveling in the opposite direction of fuel flow.

IMPORTANT: Never use a small drill bit or wire to clean the carburetor jets and orifices.

Carburetor Inspection

  1. Inspect the body of the carburetor and the top cover. Visually check for damage or cracks. If damage is found on any components, replace it with a new part. If the body of the carburetor is worn, replace that too.
  2. Inspect the carb’s needle valve seat.
  3. Inspect carburetor’s jet and nozzle.
  4. Visually inspect the needle valve assembly. If worn or broken tips are discovered, replace the assembly.
  5. Inspect the carburetor’s float.
  6. Inspect the carburetor’s auto-enrichener needle valve. If damaged tips or abnormal wear is discovered, replace the auto-enrichener.
  7. Connect the auto-enrichener positive and negative leads to a 12 V battery so as to check that the PTC heater area is heats up. The PTC heater should heat up within 5 minutes of being connected to the 12V battery.

IMPORTANT: The auto-enricher is not a serviceable part. Do not attempt to disassemble the auto-enrichener.

Never attempt to remove, disassemble or clean the Johnson outboard carburetor without the assistance of a repair manual. Additional specifications and cleaning procedures might be listed in the manual.

2 thoughts on “Johnson Carburetor Cleaning (1hp to 40 hp) 1989-2005

  • January 31, 2017 at 5:24 am

    Does this apply to my 9.9 hp Johnson 2004 outboard?

    • January 31, 2017 at 5:25 am

      Carburetor cleaning procedures pertain to the following 2-stroke and 4-stroke horsepower models:

      1990-2001 20hp Johnson
      2000-2001 3.5hp Johnson
      1990-2001 25hp Johnson
      1990-2001 5hp Johnson
      1990-2001 35hp Johnson
      1990-2001 30hp Johnson
      1990-1995 25 hp 25D Johnson
      1992-2001 2hp Johnson
      1990-1991 10 hp Johnson Comm
      2002-2004 9.9 hp Johnson
      2002-2005 9.9 hp Johnson
      1989-1990 1hp Johnson Colt/Junior
      2003-2005 15hp Johnson
      1991-2001 2.3hp Johnson
      1994-1997 15hp Johnson
      1990-2001 8hp Johnson
      1992-2001 3.3hp Johnson
      1990-1993 6.5hp Johnson
      1990-1997 28hp Johnson
      1995-1997 18hp Jet Johnson
      1993-2001 9.9hp Johnson
      1990-1996 4hp Johnson Deluxe
      1990-1998 10hp Johnson
      1990-1991 14hp Johnson
      1993-2001 6hp Johnson
      1990-2001 40hp Johnson


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