Shift Interrupter Switch Unhooked however...

[MaxGlide]

1978 Mercruiser 140, inboard, serial number 3843732
I noticed my shift interrupter switch is unhooked, however the boat seems to be shifting in and out of gear fine. Should I leave well enough alone of hook it up and check that it is adjusted?

cheers... Wayne

 

[achris]

.... Should I leave well enough alone ...

Absolutely not! That switch needs to be working or you'll (at the least) stretch the shift cable, or (at worst) get stuck in gear when you most need to come out, and smack into something that'll cost you a ton.

Chris......

 

[Scott06]

1978 Mercruiser 140, inboard, serial number 3843732
I noticed my shift interrupter switch is unhooked, however the boat seems to be shifting in and out of gear fine. Should I leave well enough alone of hook it up and check that it is adjusted?

cheers... Wayne

Yeah hook it back up. Is this a new to you boat? It likely means the shift cable was worn/dragging and killing the engine when shifting, so someone disconnected it... so you probably are in need of a lower shift cable and linkage replacement.

 

[MaxGlide]

Yeah hook it back up. Is this a new to you boat? It likely means the shift cable was worn/dragging and killing the engine when shifting, so someone disconnected it... so you probably are in need of a lower shift cable and linkage replacement.

No, we've had it two years. Seems to shift in and out fine?

 

[flashback]

You got away with it disconnected because you have a small engine, don't try it with a v8. My boat was like that when I got it and I promptly backed it into the shallows and tore up the prop. It goes into gear easily but getting back to neutral was a bear. I would hook it back up and see how it does. If everything else is good you may be surprised at the difference and when you do hook it back up be sure your in open water...

 

[Lou C]

You must have the idle set very low for it to come out of gear. I have a 4.3 in my Four Winns with the Cobra drive and if the ESA is not working it would be a bear to get out of gear which would stretch the shift cable or bend components. On the OMC the ESA doesn't totally cut the spark it lowers the idle to 450 rpm at which point it easily comes out of gear.

 

[MaxGlide]

You must have the idle set very low for it to come out of gear. I have a 4.3 in my Four Winns with the Cobra drive and if the ESA is not working it would be a bear to get out of gear which would stretch the shift cable or bend components. On the OMC the ESA doesn't totally cut the spark it lowers the idle to 450 rpm at which point it easily comes out of gear.

Hmmm… my idle is about 900rpm…

 

[MaxGlide]

You got away with it disconnected because you have a small engine, don't try it with a v8. My boat was like that when I got it and I promptly backed it into the shallows and tore up the prop. It goes into gear easily but getting back to neutral was a bear. I would hook it back up and see how it does. If everything else is good you may be surprised at the difference and when you do hook it back up be sure your in open water...

Good point. Guess I’ll look in to getting it working

 

[QBhoy]

Hmmm… my idle is about 900rpm…

I would think, if it actually was 900 rpm, you would never get her out of gear...it surely won't be that high in reality. you would be smashing into gear at that. the drive wouldn't last long at all.

 

[MaxGlide]

I would think, if it actually was 900 rpm, you would never get her out of gear...it surely won't be that high in reality. you would be smashing into gear at that. the drive wouldn't last long at all.

Very well could be much lower, honestly I don’t remember.

 

[achris]

I would think, if it actually was 900 rpm, you would never get her out of gear...it surely won't be that high in reality. you would be smashing into gear at that. the drive wouldn't last long at all.

If that 900rpm is from the dash tacho, then it could actually be way lower.

 

[MaxGlide]

Connection info. Ok, so I checked the switch, it still works. When it comes time, I will hook it up and see if the shifter is working as it should. Forgive my ignorance. One wire to ground and one to the positive terminal on the coil?

 

[achris]

Connection info. Ok, so I checked the switch, it still works. When it comes time, I will hook it up and see if the shifter is working as it should. Forgive my ignorance. One wire to ground and one to the positive terminal on the coil?

Ground and the negative (points) side of the coil. (Positive side of the coil will blow the fuse under the dash.)

 

[MaxGlide]

Ground and the negative (points) side of the coil. (Positive side of the coil will blow the fuse under the dash.)

Doh! Thanks for that! (Totally ignorant on the electrical side of things)

 

[Scott06]

Connection info. Ok, so I checked the switch, it still works. When it comes time, I will hook it up and see if the shifter is working as it should. Forgive my ignorance. One wire to ground and one to the positive terminal on the coil?

Was that in the water? It will behave differently when prop is in the water and underload.

 

[MaxGlide]

Was that in the water? It will behave differently when prop is in the water and underload.

It’s been since September but in the water. I could be wrong but I thought it was around 900rpm

Ground and the negative (points) side of the coil. (Positive side of the coil will blow the fuse under the dash.)

just to be sure, like I said I’m a dope with electrical) hook up goes like this?

 

[achris]

just to be sure, like I said I’m a dope with electrical) hook up goes like this?

Yep.