87 Alpha1: What rocks the interrupter switch?

abqrb2000

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1987 Mercruiser Alpha 1 on a 5.7 260hp. Recent purchase ans previous ower worked on it :(

PROBLEM: Hard to get into neutral.

The interrupter switch does work (manually) but is not being activated. I can't figure out what should roll the cams??

Any advice appreciated!
 

Bifflefan

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Re: 87 Alpha1: What rocks the interrupter switch?

Read this link.

It explains the workings of the interrupter system.
Its located in the adults only section of the Merc section.
Basically its the lower shift cable housing that runs the interrupter.
 

Bondo

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Re: 87 Alpha1: What rocks the interrupter switch?

I can't figure out what should roll the cams??

Ayuh,... It's the resistence of the water against the prop...
 

abqrb2000

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Re: 87 Alpha1: What rocks the interrupter switch?

Only had this boat on the water once. Had to basically tap reverse to get it to go into neutral.

According to that diagram I am wondering if I should mess with the adjustable stud?
 

Bondo

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Re: 87 Alpha1: What rocks the interrupter switch?

Nope,... You should shift Briskly....
Don't slide it, Stab it.....
 

abqrb2000

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Re: 87 Alpha1: What rocks the interrupter switch?

I'll clarify. When going forward and I want to go to neutral I have to go back in reverse before it kicks out and into neutral. The switch does work (manually) but is not being activated by the cable.

Is there a proper adjustment for this? I know bending the metal switch arm is WRONG.
 

Godfirst

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Re: 87 Alpha1: What rocks the interrupter switch?

I have the exact same setup 5.7 260, had the drive completly serviced and I really have to clank the shiffter into gear this is common on this outdrive
 

abqrb2000

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Re: 87 Alpha1: What rocks the interrupter switch?

It should go into neutral easy if the switch is working. That is what I want to achieve, neutral.
 

Don S

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Re: 87 Alpha1: What rocks the interrupter switch?

Just moving normally to neutral from either forward or reverse should work fine. Going into gear is where you don't want to hesitate, it causes the clutch dogs to chatter.
As bond-o mentioned earlier, the resistance of the water on the prop is where you get the extra movement in your shift plate that activates your shift interrupt switch. It will not happen (shouldn't happen) out of the water unless the lower shift cable is bad, or the shift shaft is binding, or drive problems.

Have you checked all the shift cable adjustments according to the OEM service manual? Don't just pick the one you think might be the problem without knowing what you are doing or you can make things a lot worse than they are.
 

abqrb2000

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Re: 87 Alpha1: What rocks the interrupter switch?

I will look into a manual. Thanks for the resposes.

I just need easy neutral. I also think the idle is high and that may effect thinks I think?
 

Fishermark

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Re: 87 Alpha1: What rocks the interrupter switch?

I also think the idle is high and that may effect thinks I think?

Yes, an idle that is too high will certainly affect the situation.


Is there a proper adjustment for this? I know bending the metal switch arm is WRONG.

Well, amazingly enough, that is exactly what you do. Bend the metal arm if the switch is not closing in time. Here's the specs:

shiftinterruptswitchadjustment.jpg
 

abqrb2000

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Re: 87 Alpha1: What rocks the interrupter switch?

Lowered idle from 1100 to 700, problem solved. It goes into neutral nice now.

Thanks all.
 
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