Mercruiser 4.3 Alpha One Stalling Into Neutral

[LIPowersports]

Typical issue stalling while shifting into neutral. Sometimes the boat almost stalls and other times it does. I checked the cable measurements all seemed fine including cable play amount. While watching the shift interuptor switch and shifting, I noticed the switch isnt always moving as it should in correlation to the cables which leads me to believe the lower cable is pinched. I also ran my hand down the lower cable and where it wraps around the y-pipe before entering the transom, the cable is schaffed some so I’m thinking the cable is binding or melted by the y-pipe? How likely is this? Also, there seems to be two switches here. Isnt there supposed to be one?

 

[Scott Danforth]

if your cable is more than 10 years old. buy a new lower shift cable

 

[LIPowersports]

if your cable is more than 10 years old. buy a new lower shift cable

Apparently everything has been changed (upper/lower cables, interuptor switch, shifter at helm and the upper Alpha drive portion.) I’ve spent hours playing with adjustments according to Mercruiser’s spec and still no luck. Cables move freely while disconnected. Sometimes the boat stalls shifting back in neutral other times it comes very close to stalling. Below are pictures. Notice theres two interuptor switches (two sets of two purple wires.) What is the lower one for?

 

[dubs283]

Top switch pictured is the shift interrupt. Lower one is the gear position switch

Gear position switch is present so the ecm knows when the drive is in gear or in neutral. Reason is for the over rev in neutral alarm/fault. Kinda superfluous but with a diagnostic tool it allows the user to see how much misbehaving the operator has performed

The two switches are unrelated as far as wiring/circuitry go even though they share a similarity with shifting

My guess is the shift cable(s) are mis adjusted or the shift assist (spring loaded device attached to the remote cable anchors) is causing a problem

If you can shift normally without the shift assist assembly in place its best to adjust the cables properly first and consider abating the shift assist

I've seen more problems caused than alleviated from the shift assist

 

[LIPowersports]

Top switch pictured is the shift interrupt. Lower one is the gear position switch

Gear position switch is present so the ecm knows when the drive is in gear or in neutral. Reason is for the over rev in neutral alarm/fault. Kinda superfluous but with a diagnostic tool it allows the user to see how much misbehaving the operator has performed

The two switches are unrelated as far as wiring/circuitry go even though they share a similarity with shifting

My guess is the shift cable(s) are mis adjusted or the shift assist (spring loaded device attached to the remote cable anchors) is causing a problem

If you can shift normally without the shift assist assembly in place its best to adjust the cables properly first and consider abating the shift assist

I've seen more problems caused than alleviated from the shift assist

Those shift assists have really caused problems? Personally I think its a cheesy idea. Maybe Ill have to try it without the shift assist linkage.