Shift Cutout

[edcourter]

I have been reading up on my Alpha Gen1 shift cable adjustments. After reading many good explanations of the cutout switch, (thanks to all), I have one nagging question. Given that the shift cable sheath is a tube with one end fixed at the outdrive casting, how can the other end of the tube move to operate the cutout lever. What am I missing.. Edward

 

[bman440440]

because it looks like this and mounts to the exhaust riser

 

[edcourter]

I still do not under stand. I have many pictures and both the Merc and Seloc Manuals. My basic confusion is how can one end of a tube (sheath) be fixed in place and the other end move? I have the dual controls (single engine) which does not have the pictured 'shift assist'. Thanks

 

[Bt Doctur]

look at how the cable are mounted and you should see your answer Without the sprinloaded assist you just have regular shifting, that all

 

[edcourter]

I can see how the lower cable sheath is on a short lever that moves the cutout cam, but I can't see where the motion comes from to move the lower cable sheath to move the cam. Is it just the friction of the cable in the sheath which drags it forward and back? Is the sheath acting like a spring due to it's bent path? Am I too stupid to pilot a boat? Thanks again, Edward

 

[Bt Doctur]

The control; cable does the pulling and pushing , the lower shift cable just responds. In fwd gear, in the water with a load on the prop the cable is pushing.
If the lower cable becomes linear action and causes the plate to move tripping the switch. Now with the control cable still under tension the motor stumbles/stalls releasing the torque for an instant allowing the plate to spring back to the V notch, and allowing the motor to run again

 

[Baylinerchuck]

I didn't really understand this mechanism at first either. Coming from outboards I was lost with this switch. Honestly at first I thought it was a safety cut out. I figured this out when I properly adjustef mine after watching a really good YouTube video. My problem was I was trying to see how it worked in my driveway. Since the prop isn't in water in the driveway the drive slips in and out of gear easily, no interrupt needed. The shift interrupt functions when the trans has a load on it, i.e. In water. When you shift out of gear in the water the transmission shift dog has a massive load on it causing the cable to bind since it can't push the transmission out of gear. As the cable binds it actuates the interrupt switch and causes the engine to stumble. This releases the pressure on transmission allowing it to shift out of gear, unbinding the shift cable. The switch kills the engine for a split second and only sounds like a misfire. That little stumble is enough to slip the transmission out of gear. Pretty ingenious if you ask me.

 

[edcourter]

Got it, Thanks to all, Edward

 

[edcourter]

I have been best able to understand the binding action by picturing the cable in its shallow S position. If the back cut gears are locked under load, the cable and the sheath are also fixed in position and move together. Pushing or pulling on the unfixed end (motor) of the S bent cable will also move the sheath at the unfixed end. Key is the fact that the cable and sheath act as one piece for that one initial second and that the cable is curved. Almost Mojo

 

[achris]

The reason the lever moves is because the lever pivot point and the cable outer sheath anchor point are offset. When the inner cable 'tightens up' due to the undercut dogs the only reaction can be that the lever moves. It's very simple mechanics.

Chris.................