06 4.3 mercruiser no start

troy lee

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06 4.3 mercruiser 0w656261. I was working on idle adjustment, starting and stopping engine. Started engine and notice some smoke from engine area, went to turn off and notice key was hung up in the start position. turned off engine and would not start again. replaced starter and it still will not start. Notice that I don't get the start light or buzzer alarm when key is turned..thanks in advance.
 

Fun Times

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Since you mentioned you had an issue with the key switch, possibly you still have a bad switch internally or something loose with the wiring behind the key switch…?

That or the smoke got something hot/burned something, blew a fuse or wire is damaged somewhere between the helm and engine.

Where you able to locate the general area of the smoke?
 

Scott06

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06 4.3 mercruiser 0w656261. I was working on idle adjustment, starting and stopping engine. Started engine and notice some smoke from engine area, went to turn off and notice key was hung up in the start position. turned off engine and would not start again. replaced starter and it still will not start. Notice that I don't get the start light or buzzer alarm when key is turned..thanks in advance.
Sounds like you are not getting 12 v to helm anymore.

May have tripped the 50 Amp breaker or slave solenoid (relay) may be smoked. If yours is carbed they are usually on a bracket behind the carb. There is also a 90 A fuse on starter lug that could be blown and interrupting the 12v supply. I think I can post a wiring diagram later
 

troy lee

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Mar 13, 2024
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Since you mentioned you had an issue with the key switch, possibly you still have a bad switch internally or something loose with the wiring behind the key switch…?

That or the smoke got something hot/burned something, blew a fuse or wire is damaged somewhere between the helm and engine.

Where you able to locate the general area of the smoke?
no I didn't really find where the smoke was coming from. I just assumed it was starter..the smoke did not smell electrical though.
Since you mentioned you had an issue with the key switch, possibly you still have a bad switch internally or something loose with the wiring behind the key switch…?

That or the smoke got something hot/burned something, blew a fuse or wire is damaged somewhere between the helm and engine.

Where you able to locate the general area of the smoke?
no ..I assumed it was starter..the smoke did not smell electrical though
 

troy lee

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Sounds like you are not getting 12 v to helm anymore.

May have tripped the 50 Amp breaker or slave solenoid (relay) may be smoked. If yours is carbed they are usually on a bracket behind the carb. There is also a 90 A fuse on starter lug that could be blown and interrupting the 12v supply. I think I can post a wiring diagram later
I see the breaker..the button will not stay in. is it supposed to stay pressed when pushed in
 

Bondo

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I see the breaker..the button will not stay in. is it supposed to stay pressed when pushed in
Ayuh,...... Welcome Aboard,....... With a test light, start at the key switch, testing for power,......

The breaker rarely goes bad, 'n when pushed in, doesn't move much anyways,.....
 

troy lee

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I sure appreciate all the help. I'm waiting on a power probe from Amazon to be delivered so I can do some testing. I'm learning quite a lot from the manual and all the advice.
 

Bt Doctur

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test both sires of the 50A breaker , must have power on both sides
Check the orange alt output on the alt, should see battery voltage unless the 90a burned out. That is the white square plastic block on the starter post.
If you forgot to connect that ,you will have no power

either just behind the carb or on the front port side of the motor,just above the water sep fuel filter
 

Dillusion808

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Hard to see but trace the wires. Might be your fuel pump relay.

My relays for the ignition were by my ignition not at the motor.
 

Fun Times

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In seeing your photo of the 50 amp breaker, Merc was having issues with that new design at the time of it opening on its own enough that they went back to the old push button design… the one you have now a yellow lever arm will drop down when it trips but sometimes it might be hard to tell it dropped… make sure you reset it ensuring a good pushed in/up locking position.

Have to push the red button then move the yellow lever.

See if that helps… even if it doesn’t, you still need to know it can cause issues someday.

Always carry a test light on board the boat as often enough losing power is something simple from a loose, vibration effected wire, etc.

 

troy lee

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test both sires of the 50A breaker , must have power on both sides
Check the orange alt output on the alt, should see battery voltage unless the 90a burned out. That is the white square plastic block on the starter post.
If you forgot to connect that ,you will have no power

either just behind the carb or on the front port side of the motor,just above the water sep fuel filter
no power across 50A breaker and 12v on orange wire at alternator..I guess I need new breaker?
 

Dillusion808

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Just making sure by saying no voltage across the breaker you don't have the meter or test light hooked up to both sides do you?

You need one side to ground.

You try to reset it like Fun Times mentioned?
 
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