5005561 JOHNSON CARBURETOR Assy, Port, 90HP

During operation, the oxygen sensor may reach temperatures that exceed 700 °C (1292 °F). Severe personal injury and property damage will result from contact with a hot oxygen sensor.Do not touch the sensor during engine operation, calibration, or testing. Allow the sensor to cool before moving the sensor. Wear gloves that resist heat. Do not place the sensor on or near any flammable material or any surface that can be damaged by high temperatures.
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.
Thoroughly inspect the following connectors:
Connectors for the ECM
Connectors for the oxygen sensor and the oxygen buffer
Check the harness and wiring for abrasion and pinch points from the oxygen sensor to the ECM.Expected Result:All of the connectors, pins, and sockets are connected properly. The connectors and the wiring are free of corrosion, abrasion, and pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - At least one of the connectors, pins, or sockets are not connected properly. At least one of the connectors or the wiring has corrosion, abrasion, and/or pinch points.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check the Atmospheric Conditions
Determine the ambient temperature, relative humidity, and barometric pressure.
Use Table 1 to determine whether your relative humidity is within the permissible range for calibration of the oxygen sensor.
Find the row for your ambient temperature.If the temperature is less than 12 °C (54 °F), use the 12 °C (54 °F) row.If the temperature is more than 38 °C (100 °F), do not calibrate the sensor.
Find the column for your barometric pressure.
Find the relative humidity in the cell that intersects your column and your row.If your relative humidity is equal to the humidity or greater than the humidity that is listed in the Table, do not calibrate the sensor.If the humidity is 90 percent or more, do not calibrate the sensor.
Table 1
Ambient Temperature, Barometric Pressure, and Relative Humidity for Calibration of the Oxygen Sensor    
Ambient Temperature     Barometric Pressure    
96 kPa (13.9 psi)
97 kPa (14.7 psi)    
99 kPa (14.4 psi)    
101 kPa (14.6 psi)    
102 kPa (14.8 psi)    
104 kPa (15 psi)    
105 kPa (15.2 psi)    
107 kPa (15.5 psi)    
109 kPa (15.8 psi)    
110 kPa (16 psi)    
112 kPa (16.2 psi)    
113 kPa (16.4 psi)    
Relative Humidity
12 °C (54 °F)     90     90     90     90     90     90     90     90     90     90     90     90    
14 °C (57 °F)     85     85     85     85     90     90     90     90     90     90     90     90    
16 °C (61 °F)     75     75     75     75     80     80     80     80     85     85     85     85    
18 °C (64 °F)     65     65     65     70     70     70     70     75     75     75     75     75    
20 °C (68 °F)     60     60     60     60     60     65     65     65     65     65     65     70    
22 °C (72 °F)     50     50     55     55     55     55     55     60     60     60     60     60    
24 °C (75 °F)     45     45     45     50     50     50     50     50     50     55     55     55    
26 °C (79 °F)     40     40     40     45     45     45     45     45     45     45     50     50    
28 °C (82 °F)     35     35     40     40     40     40     40     40     40     40     45     45    
30 °C (86 °F)     35     35     35     35     35     35     35     35     35     40     40     40    
32 °C (90 °F)     30     30     30     30     30     30     35     35     35     35     35     35    
34 °C (93 °F)     25     25     30     30     30     30     30     30     30     30     30     30    
36 °C (97 °F)     25     25     25     25     25     25     25     25     25     30     30     30    
38 °C (100 °F)     20     25     25     25     25     25     25     25     25     25     25     25    Expected Result:The temperature is less than 38 °C (100 °F). The ambient relative humidity is within the permissible range for calibration of the oxygen sensor.Results:
OK - The ambient conditions are acceptable. Proceed to Test Step 3.
Not OK - The humidity is not acceptable.Repair: Do not calibrate the sensor until the humidity is acceptable.STOPTest Step 3. Check for Diagnostic Codes
Restore the electrical power to the engine. Set the engine control to the STOP mode.
Use an electronic service tool in order to check for the following codes. If the following codes are activated, clear the codes:
550-02 Noisy or Loss of Oxygen Signal
551-01 Oxygen Sensor not connected to buffer