mercruiser alpha one shuts off intermittantly when shifting into reverse

[randysmith01@gmail.com]

I have a 1987 5.7L Mercruiser Alpha one that intermittently shuts off when I shift into reverse. Since this occurs when I am docking, it is a real problem. Does anyone know the likely source of this problem?

I am assuming that it is a faulty cutoff switch, but I am told Mercruiser no longer makes the original cutoff switch and that I need to change out the assembly to replace a faulty cutoff switch (which I am reluctant to do without knowing that it is the source of the problem. Any suggestion on how to fault isolate this problem would be appreciated.

 

[tommays]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

It would most likely be a lower shift cable , when they get old they do not move well and hold the shift switch to long

Tommays

 

[Bondo]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

Ayuh,............

99% of the time,......... It's the Cable,+ Not the Switch..........

 

[randysmith01@gmail.com]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

It would most likely be a lower shift cable , when they get old they do not move well and hold the shift switch to long

Tommays

 

[randysmith01@gmail.com]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

Thank you.

Randy

 

[Woody-jh]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

I have the same problem, primarily when the leaving the dock after launch from trailer. Stalled engine is no fun! After a replacement engine was installed, (late 2006), the replacement 4.3 Merc now runs at 105 degF instead of 145 degF like the old motor. I wondered if my problem was the thermostat failing open, not allowing the engine to heat up. The boat is still winterized, but I will check the thermostat and the cable based on your experience. The gauge shows 105 degrees, and the water flowing out the exhaust is about that temp

 

[capecodder116]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

I have the same intermitent shift problem while docking with a 1984, 5.7 mercrusier. Can the inner cable be replaced alone or is it necessary to replace the inner cable and the outer jacket as one entire assembly?

 

[Limited-Time]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

I have the same intermitent shift problem while docking with a 1984, 5.7 mercrusier. Can the inner cable be replaced alone or is it necessary to replace the inner cable and the outer jacket as one entire assembly?

The entire assembly must be replaced. Changing just the core won't help, and would be a waste of your time.

 

[Bondo]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

Ayuh,.......

The Merc. Lower Shift Cable is somewhat of a Unique utilization of a Cable,+ Sheath,......

Normally,... The Sheath is Anchored Solid,+ Just the Inner Cable is doing All the work,.....
But with the Merc. Lower Shift Cable,......
It's actually the Outer Sheath that activates the Shift-Interupter,+ allows the Inner to complete It's Job........

And,...... The Best Reason to change the Whole Thing is,......
It's Usually the Outer Sheath that's Worn..........Inside where you Can't see it of course......

 

[crazy charlie]

Re: mercruiser alpha one shuts off intermittantly when shifting into reverse

Most of the time there is nothing wrong at all.Shifting too slowly will stall a mercruiser.You cant baby the shift lever.You must make a definite shift.Not too fast and not too slow.Cant determine whether that is your problem or not but try shifting with a bit more authority and see if it stalls.Charlie