Johnson 150 V6 Ocean Runner - not starting

[rich_benson]

Rebuilt the carbs, new plugs, and starter. Was running for a month and then no more. Heavy black deposits on NGK plugs I had in there....went and bought new Champion spark plugs (per another iboats thread) and they wont even generate a spark when I test them. The NGK's still generate a spark, but the engine wont fire up. When turning it over, lots of oil coming out from prop. I dont see a lean/rich oil adjustment on these 6 carbs so would love to know if and where the adjustment screws are.
The engine turns over fine, just seems to not fire...

 

[racerone]

Model # is ??

 

[rich_benson]

Model # is ??

1993 Johnson 150 V6 Ocean Runner 60 degree​

 

[rich_benson]

This is all i have left on the model # tag

 

[Chris1956]

Have you tested for spark? That motor likely has a shift assist switch that kills spark to 1/2 the motor. It also has overheat sensors that kill spark. If either malfunction, spark is compromised.

 

[rich_benson]

I was able to get a spark with the NGK plugs. I only tested two of the six cylinders on one bank. The spark seemed weak to me, but it was present.

 

[rich_benson]

Have you tested for spark? That motor likely has a shift assist switch that kills spark to 1/2 the motor. It also has overheat sensors that kill spark. If either malfunction, spark is compromised.

Also, original wiring from 1993 does not look to be 100%…pretty sure one of the overheat sensors isn’t wired right.

 

[rich_benson]

Have you tested for spark? That motor likely has a shift assist switch that kills spark to 1/2 the motor. It also has overheat sensors that kill spark. If either malfunction, spark is compromised.

Thank you. Do you know if there are specific cylinders it disables electric on the coil from?

 

[oldboat1]

Test for spark with a device meant for that -- buy an adjustable open air tester and set it for 3/8. You are testing the strength of the ignition system.

Make sure connections (battery) are sandpaper clean and shiny, and the battery is fully charged.

 

[rich_benson]

Test for spark with a device meant for that -- buy an adjustable open air tester and set it for 3/8. You are testing the strength of the ignition system.

Make sure connections (battery) are sandpaper clean and shiny, and the battery is fully charged.

Thank you. I did use a wire brush on plugs, but the wiring bundle near back of engine, appears to have significant corrosion so I suspect all of it to be original wiring - 1993 (like the starter was). So likely that I do have a poor ignition system (low spark which is highly likely). Batteries charged and cleaned, plenty of starter power, but weak spark. What is the next part in the path, spark plug caps - coils, stator, other electrical components.

 

[rich_benson]

Thank you. I did use a wire brush on plugs, but the wiring bundle near back of engine, appears to have significant corrosion so I suspect all of it to be original wiring - 1993 (like the starter was). So likely that I do have a poor ignition system (low spark which is highly likely). Batteries charged and cleaned, plenty of starter power, but weak spark. What is the next part in the path, spark plug caps - coils, stator, other electrical components.

Lets say it was the powerpack that needed replacing (if no good spark is present) is that fair assumption?

 

[dingbat]

Lets say it was the powerpack that needed replacing (if no good spark is present) is that fair assumption?

Before you go broke blindly changing parts, take the time to troubleshoot the problem. This should get you through the process

https://www.cdielectronics.com/wp-content/uploads/2013/02/CDI%20Troubleshooting%20Guide%20-%202012.pdf

 

[rich_benson]

Before you go broke blindly changing parts, take the time to troubleshoot the problem. This should get you through the process

https://www.cdielectronics.com/wp-content/uploads/2013/02/CDI%20Troubleshooting%20Guide%20-%202012.pdf

Thank you Sir.

 

[Chris1956]

A lot of those motors use battery voltage to the powerpack, when the engine is cranking, to generate spark. You might look for the red/yellow wire from the starter solenoid to the powerpack. Maybe it broke or got dirty.

 

[rich_benson]

Thank you Sir.

To help others this did the trick to get the engine to fire

NO FIRE AT ALL: 1. Check the kill lanyard and key-switch position. 2. Verify the engine rotation (The engine needs to be turning in a clockwise direction). 3. Check the power pack and ignition coil ground wires for corrosion and tightness. 4. Connect a spark gap tester to all cylinders. 5. Disconnect the boat side harness and connect a remote starter unit. Check for spark. If the engine has spark, check the boat side harness’s Black/Yellow wire for shorts to ground. 6. Disconnect the 5-pin connector on the port side of the power pack and see if the spark returns. If it does, use the Fluke meter set to Ohms and see if the Black/Yellow wires are shorted to engine ground. 7. Check the battery voltage on the Yellow/Red striped wire while cranking the engine. If below 11 volts, charge the battery or check all battery cables. If the battery continues to read below 11 volts at cranking, verify the starter is not dragging. 8. Remove the sensor wheel and check for damage, especially where the top slots are located. Sometimes the wheels will break out where the windows overlap. 9. Check the sensor eyes for dirt, grease, etc. If you have to clean it, use denatured alcohol and a Q-tip. Do not use any other cleaning agent because damage to the optical lens will occur. 10. Disconnect the voltage regulator/rectifier and retest. If the engine now has spark, replace the regulator/rectifier. 11. Using the Piercing Probes,

 

[Chris1956]

Gee, WTF, over

 

[rich_benson]

To help others this did the trick to get the engine to fire

NO FIRE AT ALL: 1. Check the kill lanyard and key-switch position. 2. Verify the engine rotation (The engine needs to be turning in a clockwise direction). 3. Check the power pack and ignition coil ground wires for corrosion and tightness. 4. Connect a spark gap tester to all cylinders. 5. Disconnect the boat side harness and connect a remote starter unit. Check for spark. If the engine has spark, check the boat side harness’s Black/Yellow wire for shorts to ground. 6. Disconnect the 5-pin connector on the port side of the power pack and see if the spark returns. If it does, use the Fluke meter set to Ohms and see if the Black/Yellow wires are shorted to engine ground. 7. Check the battery voltage on the Yellow/Red striped wire while cranking the engine. If below 11 volts, charge the battery or check all battery cables. If the battery continues to read below 11 volts at cranking, verify the starter is not dragging. 8. Remove the sensor wheel and check for damage, especially where the top slots are located. Sometimes the wheels will break out where the windows overlap. 9. Check the sensor eyes for dirt, grease, etc. If you have to clean it, use denatured alcohol and a Q-tip. Do not use any other cleaning agent because damage to the optical lens will occur. 10. Disconnect the voltage regulator/rectifier and retest. If the engine now has spark, replace the regulator/rectifier. 11. Using the Piercing Probes,

Engine fired up immediately so it was a shorted (disconnected / rotted ) ground wire

 

[Chris1956]

Shorted ground wire? Do you mean dirty ground wire connectors or broken ground wire?

 

[rich_benson]

Shorted ground wire? Do you mean dirty ground wire connectors or broken ground wire?

Broken/disconnected from wire harness - from salt water over 30 years