Starting

[Roach12]

My boat will not start in neutral but it will start in forward or reverse but the second I go into neutral it dies. What would cause this? It’s a 1976 mercruiser 165 inline 6

 

[Kola16]

Probably something electrical like your shift interrupt switch. There is a switch that gets stuck on your shift cable mounting plate. When the interrupt switch is pressed, your motor cannot run.

 

[achris]

My boat will not start in neutral but it will start in forward or reverse but the second I go into neutral it dies. What would cause this? It’s a 1976 mercruiser 165 inline 6

'Won't start', means ? Won't crank, or cranks but won't fire?

Chris........

 

[Bt Doctur]

My boat will not start in neutral but it will start in forward or reverse but the second I go into neutral it dies

You should not be able to crank the motor in gear, so fix that first. If you are starting in gear and dying when shifting back to neutral the shift interrupter is activating from a bad lower shift cable or corrosion in the shift mechanism. Pull the drive to inspect everything

 

[Kola16]

Notice where the roller is inside the crimson circle in the picture. The roller needs to be in that divot to start the boat. When the switch in the bottom center of the picture is depressed, it kills the engine momentarily to allow your motor to shift.

 

[Roach12]

Notice where the roller is inside the crimson circle in the picture. The roller needs to be in that divot to start the boat. When the switch in the bottom center of the picture is depressed, it kills the engine momentarily to allow your motor to shift.

Mine is exactly how it is in the picture. Only thing I can think of is maybe it needs to be bent just a little bit because maybe it’s pressing in the switch slightly?

 

[Kola16]

Mine is exactly how it is in the picture. Only thing I can think of is maybe it needs to be bent just a little bit because maybe it’s pressing in the switch slightly?

Possibly. A way to test if the switch is pressed too much would be to remove one of the screws from the switch. The limit switch would then be free from the interrupter contraption (the 'Y' with the springs) and not depressed at all and try to start it in neutral. But like Bt Doctur said, you should not be able to start it in gear. When you do start it in gear does the prop spin immediately? Also does it crank when in neutral?

 

[Roach12]

The button is pulled when starting it. If the button is pushed in and throttle pushed forward it won’t allow you to start it. It does crank when in neutral and the prop doesn’t spin when starting. Only other thing I can think of is a bad lower cable.

 

[Kola16]

When your shifter is in neutral, can you spin the prop by hand (without starting the motor)? Can you spin the prop in forward and reverse? The prop should be able to spin freely in neutral and locked in both forward and reverse. The motor does not have to be running to test this.

Also if the lower shift cable has never been changed since 1976, then that could be the problem like BT said. They were known to go bad and changed to a new style cable.

 

[achris]

... The prop should be able to spin freely in neutral and locked in both forward and reverse. ....

No... The prop should free-spin in neutral only.

In forward, it should ratchet when turned CW (forward), and lock when turned CCW.
In reverse, it should ratchet when turned CCW (reverse), and lock when turned CW.

Chris.......

 

[Roach12]

My prop spins freely in both directions when I’m neutral and in forward it turns clockwise and locks turning CCW. In reverse it’s the opposite so all of that is correct. I’m not sure if the lower shift cable has ever been replaced as I inherited the boat. Is it possible to have a boat not start on land with muffs with this problem and start in the water due to the load that’s put on it? Also, if the timing was off would that effect the boat not being able to start in neutral? Otherwise it sounds like she needs a new lower shift cable.

 

[achris]

The problem you have is very unlikely to be the shift cable. Try bypassing the neutral switch in the shift control box...