Shift Interupter won't center after shifting.

[Condor1970]

1989 Merc 3.0L w/ Alpha One Gen 1 outdrive. Pinned shifting cable barrel. lower shift cable has only 1/8" loose play.

I don't understand this. My shift interrupter won't center itself after shifting. It stays to one side, and kills the engine by pressing the switch. I've adjusted it in accordance with the manual, and it is centered for idle, but when I go forward or reverse, the shift interrupter won't move back to the center. The problem is the lower shift cable pulls it over to forward or reverse, but there is no tension released to allow the interrupter to center.

Can someone give me an idea of what to do here?

 

[alldodge]

1989 Merc 3.0L w/ Alpha One Gen 1 outdrive. Pinned shifting cable barrel. lower shift cable has only 1/8" loose play.

I don't understand this. My shift interrupter won't center itself after shifting. It stays to one side, and kills the engine by pressing the switch. I've adjusted it in accordance with the manual, and it is centered for idle, but when I go forward or reverse, the shift interrupter won't move back to the center. The problem is the lower shift cable pulls it over to forward or reverse, but there is no tension released to allow the interrupter to center.

Can someone give me an idea of what to do here?

How old is the lower shift cable?

 

[Condor1970]

Well, as far as I know, it is stock. I did notice it takes a bit of "oomph" to get it to move. It does move smoothly, but requires a bit of push. Is this normal?

Is it supposed to be super easy to move?

Like 2 finger easy?

 

[thumpar]

Sounds like it is time for a new lower shift cable.

 

[alldodge]

+1 on the lower shift cable. While your at it check all those other things back there and make sure there up to snuff

 

[Condor1970]

I already had the bloody lower off to service the U-joints and replace the impeller. Now a shift cable?

It does operate smoothly. I don't get it.

As far as adjusting goes. When the lower is all the way forward gear with the interrupter centered, and the shift lever all the way forward, shouldn't I be able to rotate the barrel on the upper shift cable enough to center it on the pins?

The upper shift cable is about 1/4" short with the barrel all the way back against the rear of the adjustment. The only way to center it would be to remove about 1/4" off the lower cable to move it back far enough for the upper to center itself with the interrupter centered as well.

 

[thumpar]

The lower shift cable can wear a groove in the sheath and will loose travel. It is a commonly replaced part.

 

[Bt Doctur]

There is noting to add to ,or remove from a shift cable. it works correctly right out of the box. Do you have the merc manual?

 

[Malibu-m1700]

I had the same issue with mine, it worked good trimmed all the way up most of the time when lowered a bit I had this issue. I found the exhaust bellow was stiff & would bind when trimmed down any amount, I replaced the bellow & everything worked great. My boat has a 4.3 with a alpha 1 drive.

 

[thumpar]

The exhaust bellows would not effect the shift interrupt switch.

 

[Malibu-m1700]

It did on my mine, it would push the cable & not allow it move freely. With the drive trimmed up the bellow was stretched tight & all worked fine. When trimmed down & the boot collapsed the cable would not move freely & the ignition would quit. I replaced the boot & haven't had a issue since.

 

[matth121]

theres a great post about the shift interrupt system in the adults only section at the top of this forum. from that - there is a bolded note that reads As a trouble shooting note: If your shift interrupt switch is being activated going into either forward or reverse or coming out of gear when the boat is out of the water, then you have a problem with something binding from the lower shift cable to the drive itself.

any chance it didnt go back together right when you had the lower off?

 

[Condor1970]

any chance it didnt go back together right when you had the lower off?[/B]

Well, we'll know when I pull the outdrive again to install a new shift cable. I bought one, and it should be getting here later this week. Hopefully next weekend, I'll have a deinfitive answer.

 

[matth121]

good luck, please let us know how it goes!