Mercruiser Alpha One dies when shifting to reverse

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allingeneral

Petty Officer 3rd Class
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Hi all,

My Mercruiser is a 1989 350 Chevy power pack with an Alpha One outdrive.

When I shift from neutral to reverse, it dies - almost every time.
It goes into forward gear just fine, every time.
It tries to die (and sometimes succeeds) shifting into neutral from either direction.

I found a thread about adjusting the throttle cables, as it seems that they may be getting out of sync and causing the ignition interruptor to engage.

Which cable should I be looking at, and do I need to tighten or loosen it?

Does anyone have a diagram or illustration that shows how these cables work?

I found that if I want to replace the switch, I would have to replace the entire throttle plate. I think the switch is working fine, though - so I probably won't be doing that.

Thanks for your assistance!
 

HT32BSX115

Supreme Mariner
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Messages
10,083
Re: Mercruiser Alpha One dies when shifting to reverse

Howdy,

Just look up at the "Adults Only" sticky
There's info there including downloadable service manuals.


It sounds like your shift cable might be a bit sticky or in need of adjustment.

Regards,


Rick
 

allingeneral

Petty Officer 3rd Class
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Re: Mercruiser Alpha One dies when shifting to reverse

Yessiree! Thank you Rick. The manual that you linked to is exactly what I needed!

Thanks!
Rick
 

Bondo

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71,132
Re: Mercruiser Alpha One dies when shifting to reverse

Which cable should I be looking at, and do I need to tighten or loosen it?

Ayuh,.... It's the Lower Shift Cable,+ it doesn't need Adjusting, it needs Replacing...
 

allingeneral

Petty Officer 3rd Class
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81
Re: Mercruiser Alpha One dies when shifting to reverse

Ayuh,.... It's the Lower Shift Cable,+ it doesn't need Adjusting, it needs Replacing...

Can you explain in a little more detail? What's wrong with the cable? Is is stretched from years of use? Corrosion?
 

Bondo

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Re: Mercruiser Alpha One dies when shifting to reverse

Ayuh,... The cable Wears,... Then it Drags, That's Why it stalls out the motor....
 

ziggy

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Re: Mercruiser Alpha One dies when shifting to reverse

Can you explain in a little more detail?
or, back to the adults only sticky and check out #4...
 

HT32BSX115

Supreme Mariner
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10,083
Re: Mercruiser Alpha One dies when shifting to reverse

Those cables do get "sticky" but it is usually from water instrusion/corrosion etc.

That usually takes a fair amount of time. If that has been happening you can expect the shift cable rubber boot to possibly be cracked/leaking etc.

When it gets that bad you usually need to have a look at everything else in there. drive bellows, exhaust bellows, shift bellows (boot)..

While you maybe *could* lube the cable it would be a temp fix at best since the other stuff needs attention....any binding in the cable will almost ALWAYS give you trouble activating the ignition-interrupt switch when it shouldn't.

Plan on replacing the cable and if the drive bellows even looks bad you need to replace it too. Do the exhaust bellows while you're there too although it's not as important. (you can even run without it....although I wouldn't)

You can usually buy a "transom-service" kit that has most of the "stuff" to do the job.


Cheers,


Rick
 

mylesm260

Chief Petty Officer
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Sep 13, 2007
Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

I'm having the exact same problem.

Except I have brand new bellows and a brand new shift cable.

I've had the drive off aswell, and I'm sure there's no water that's leaked in. From day 1 after changing the cable and bellow my reverse has caused engine stalling.
 

cooter2506

Senior Chief Petty Officer
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Messages
733
Re: Mercruiser Alpha One dies when shifting to reverse

myslesm260 you need to adjust yours correctly. Same situation but different problem his needs replaced. Go to the adult stickys and download your manual and read up on adjusting your cable. If you have problems start another thread to not confuse the people helping allingeneral
 

JustJason

Vice Admiral
Joined
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Messages
5,321
Re: Mercruiser Alpha One dies when shifting to reverse

You may want to think about giving your boat a full tune up first.
When the cable goes south, the engine will stall when coming out of gear going into neutral..... not the other way around.
 

mylesm260

Chief Petty Officer
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Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

My motor's efi'ed and never stalls under normal circumstances.

I can shift from neutral to drive and back 500 times, and it won't stall once, it just does the sort of half stutter when the shift interrupt kicks in and the coil cuts out.


I locked the prop in gear, and adjusted the lower shift cable to 6", then I started adjusting my upper cable, and I still haven't been able to get it to shift into reverse reliably.

I can get it to shift in the driveway with the muffs on perfectly, just not while in the water.
 

boatguya1

Chief Petty Officer
Joined
Apr 24, 2009
Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

Those cables do get "sticky" but it is usually from water instrusion/corrosion etc.

That usually takes a fair amount of time. If that has been happening you can expect the shift cable rubber boot to possibly be cracked/leaking etc.

When it gets that bad you usually need to have a look at everything else in there. drive bellows, exhaust bellows, shift bellows (boot)..

While you maybe *could* lube the cable it would be a temp fix at best since the other stuff needs attention....any binding in the cable will almost ALWAYS give you trouble activating the ignition-interrupt switch when it shouldn't.

Plan on replacing the cable and if the drive bellows even looks bad you need to replace it too. Do the exhaust bellows while you're there too although it's not as important. (you can even run without it....although I wouldn't)

You can usually buy a "transom-service" kit that has most of the "stuff" to do the job.


Cheers,


Rick

My experience is that the water comes in through the bell hsg shift shaft seal/bshg. It goes from the exhaust area (always wet) to the shift cavity that should always be dry. You can change every bellows on the boat and it won't solve this. I put a new seal/bshg on every boat I put a cable on.

James
 

boatguya1

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Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

My motor's efi'ed and never stalls under normal circumstances.

I can shift from neutral to drive and back 500 times, and it won't stall once, it just does the sort of half stutter when the shift interrupt kicks in and the coil cuts out.


I locked the prop in gear, and adjusted the lower shift cable to 6", then I started adjusting my upper cable, and I still haven't been able to get it to shift into reverse reliably.

I can get it to shift in the driveway with the muffs on perfectly, just not while in the water.

If you did not screw the shift cable far enough into the bell hsg it could cause this. Can't remeber right now but I think it's a max of three threads showing could be two.

James
 

mylesm260

Chief Petty Officer
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Messages
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Re: Mercruiser Alpha One dies when shifting to reverse

If you did not screw the shift cable far enough into the bell hsg it could cause this. Can't remeber right now but I think it's a max of three threads showing could be two.

James

Yup, that sounds like it must be the problem. Can anyone else confirm this?
 

Bt Doctur

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Re: Mercruiser Alpha One dies when shifting to reverse

It`s in the manual, no more than 2 threads visable
 

mylesm260

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Re: Mercruiser Alpha One dies when shifting to reverse

Yup, I know that part, I've read the manual just now, but my question is, lets say I have 4 threads visible, will that cause this problem?

I just want to know before I go and order another gasket kit and take my drive off.

I've tried adjusting the shift cables on the engine side, so I'm 99% sure they arn't the problem.
 

boatguya1

Chief Petty Officer
Joined
Apr 24, 2009
Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

Yup, I know that part, I've read the manual just now, but my question is, lets say I have 4 threads visible, will that cause this problem?

I just want to know before I go and order another gasket kit and take my drive off.

I've tried adjusting the shift cables on the engine side, so I'm 99% sure they arn't the problem.

Not saying it is the problem but it could be. If not screwed in far enough the part on the end of the cable that the roller slides into will hit the cable hsg prior to moving far enough to engauge reverse. When it hits the hsg it gives resistance to the cable moving and that acuates the shift cutout switch killing the motor.

James
 

boatguya1

Chief Petty Officer
Joined
Apr 24, 2009
Messages
444
Re: Mercruiser Alpha One dies when shifting to reverse

Also make sure you remove the shift bellows from the transom hsg prior to screwing the cable in more or atleast loosen up the pinch clamp on the cable end and watch it so it does not twist up.

James
 

ArmyDoc

Cadet
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Jul 23, 2020
Messages
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Is it possible then that if the bottom cable only is out of adjustment by a few threads that it would engage the engine cutoff into drive and reverse? Or in one direction only?
 
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