4.3 mercruiser wont shift out of gear unless motor shut off.

[thegoat86]

Made it interesting to dock boat today. Is this an adjustment issue, or a larger problem? Does anyone have a link to correctly adjusting the cables? 91' Larson with alpha one drive.

 

[alldodge]

Made it interesting to dock boat today. Is this an adjustment issue, or a larger problem? Does anyone have a link to correctly adjusting the cables? 91' Larson with alpha one drive.

My guess is the shift interrupter switch adjustment. Go to the top of this section in DonS adults only section and look up achris videos. The alpha drive needs the shift interrupter switch to work or you cannot get it out of gear

 

[Bondo]

Ayuh,.... Before ya go adjustin' things, check the wirin' for the interrupter switch 1st,....

Push the button/ lever 'n see if it'll stall the motor,....

 

[Fishermark]

Ayuh,.... Before ya go adjustin' things, check the wirin' for the interrupter switch 1st,....

Push the button/ lever 'n see if it'll stall the motor,....

Yep. Many times people will disconnect the switch because the engine keeps dying when coming out of gear. They somehow think the switch is bad or something. The problem usually lies in the shift cable being bad instead.

If engaging the switch manually kills the engine, then you might simply have an adjustment problem.

 

[thegoat86]

Ok, I read how it works. Is there a link to adjustment on here?

 

[airshot]

Look inside your mercruiser factory service manual, read carefully and follow instructions....do not cut corners and you will be just fine. Of course every responsible boat owner that makes his own repairs has a factory service manual and would never rely on another's backyard doit yourself description. LOL

 

[thegoat86]

"Of course every responsible boat owner that makes his own repairs has a factory service manual"

Firing shots across the bow is not very forum friendly airshot. If you don't have the info to HELP others who need it, don't chime in.

 

[alldodge]

Here is a link to achris video for shift cable adjustment from up in the Adults only section.
http://www.youtube.com/watch?v=-s_tgevX2aI&feature=youtu.be

Here is a link to the service manual
http://boatinfo.no/lib/mercruiser/manuals/mercruiser14.html#/66

 

[thegoat86]

Gracious alldodge. I just downloaded and read through the entire OMC manual linked here and couldn't find the adjustment. Plus I am a newbie here and having trouble navigating this sites waters. I really did try to look for the achris section.

 

[alldodge]

Gracious alldodge. I just downloaded and read through the entire OMC manual linked here and couldn't find the adjustment. Plus I am a newbie here and having trouble navigating this sites waters. I really did try to look for the achris section.

The video is on U tube and can be an issue if your down load speed isn't high enough. The service manual is on boatinfo and also takes a while to bring it up. Below is a link for a PDF download of the Merc service bulletin which should help you get the adjustment accomplished.

http://www.boatfix.com/merc/bullet/89/89_04.PDF

Edit: you mentioned above the "OMC manual", this is a Mercruiser right?

 

[thegoat86]

Maybe I mistyped. Its a 4.3 mercruiser. 91 Larson. So, I made the adjustment according to the PDF sent. I followed the directions. Forward works great. shift interrupter switch works then goes back to center as I throttle. The shift interrupter switch engages in all aspects of reverse. Soooo. I looked for discrepancies in the manual to my application. I have the plastic shift bracket. However, my cable that goes to the remote is adjustable. It has a threaded rod and a smaller brass jam nut. Both of which are loose and turn freely. I assume the problem lies somewhere in there. As I put it in reverse, there is a lot of pressure pushing the shift bracket. Which translates to tension on the interrupter keeping it engaged. Not letting go. Any ideas? Or am I looking at just getting another cable? I am a don't replace it until its broken kind of guy.

 

[alldodge]

Maybe I mistyped. Its a 4.3 mercruiser. 91 Larson. So, I made the adjustment according to the PDF sent. I followed the directions. Forward works great. shift interrupter switch works then goes back to center as I throttle. The shift interrupter switch engages in all aspects of reverse. Soooo. I looked for discrepancies in the manual to my application. I have the plastic shift bracket. However, my cable that goes to the remote is adjustable. It has a threaded rod and a smaller brass jam nut. Both of which are loose and turn freely. I assume the problem lies somewhere in there. As I put it in reverse, there is a lot of pressure pushing the shift bracket. Which translates to tension on the interrupter keeping it engaged. Not letting go. Any ideas? Or am I looking at just getting another cable? I am a don't replace it until its broken kind of guy.

It appears from what your telling us that the shift cable needs to be replaced, This is an item which is replaced often in older boats with hours on them. Not saying that this is the issue, but saying that from what I'm hearing from your discussion, this is what I would replace if I followed the adjustment and had the same issue

 

[Bondo]

Maybe I mistyped. Its a 4.3 mercruiser. 91 Larson. So, I made the adjustment according to the PDF sent. I followed the directions. Forward works great. shift interrupter switch works then goes back to center as I throttle. The shift interrupter switch engages in all aspects of reverse. Soooo. I looked for discrepancies in the manual to my application. I have the plastic shift bracket. However, my cable that goes to the remote is adjustable. It has a threaded rod and a smaller brass jam nut. Both of which are loose and turn freely. I assume the problem lies somewhere in there. As I put it in reverse, there is a lot of pressure pushing the shift bracket. Which translates to tension on the interrupter keeping it engaged. Not letting go. Any ideas? Or am I looking at just getting another cable? I am a don't replace it until its broken kind of guy.

Ayuh,.... If this is on the wagon, 'n not in the water,.... Yer lower shift cable is bindin', 'n needs replacin',....

 

[Fishermark]

...Forward works great. shift interrupter switch works then goes back to center as I throttle. The shift interrupter switch engages in all aspects of reverse. ...

If everything is working right and the cable is adjusted correctly, then the switch will not engage at all when going into gear. ONLY when coming out of gear. If it is engaging when you put it into gear - either forward or reverse, you either have the adjustment wrong, or the cable is bad.

I too am a "don't replace it till it breaks" kinda guy... but the shift cable is a different story on Mercruisers. It can start to bind for a whole host of reasons, and the only solution is to replace it.

But you never did answer the original question. Was your interrupt switch disconnected or not working before? Does it kill the engine when you manually engage the switch?

 

[thegoat86]

yes, switch does work. I tested that first. I can tell the guy I bought the boat from had issues with this and must have given up. He had a ground wire going from the switch to ground out the distributor because he could not turn of the ignition. I posted on another thread about that issue and got it fixed.

The linkage does a weird thing. Let me explain in long winded form.

Before and after adjusting; I push the throttle forward, it engages the drive, I throttle up, but past a point the linkage to the card drops back and then kills the ignition. That is pushing it all the way until it stops. Same in reverse. So, I might have multiple issues, or it may be working to protect the engine. I watched the video on adjustment. But am still unclear, Do I stop pushing the throttle in forward as soon as it goes into gear to adjust that cable? Or do I push until it moves the linkage on the carb into full throttle?

 

[Bondo]

yes, switch does work. I tested that first. I can tell the guy I bought the boat from had issues with this and must have given up. He had a ground wire going from the switch to ground out the distributor because he could not turn of the ignition. I posted on another thread about that issue and got it fixed.

The linkage does a weird thing. Let me explain in long winded form.

Before and after adjusting; I push the throttle forward, it engages the drive, I throttle up, but past a point the linkage to the card drops back and then kills the ignition. That is pushing it all the way until it stops. Same in reverse. So, I might have multiple issues, or it may be working to protect the engine. I watched the video on adjustment. But am still unclear, Do I stop pushing the throttle in forward as soon as it goes into gear to adjust that cable? Or do I push until it moves the linkage on the carb into full throttle?

Ayuh,..... It don't matter, the shift cables, 'n throttle cable's only connection is in the controller,....
Once the shift cable moves to forward, or reverse, that's it, regardless the position of the throttle,...

Though ya Might have a controller issue, I'd sooner think the lower shift cable is gummed up, 'n draggin', causin' yer issues,....

 

[thegoat86]

Remedy = replace "all" cables and try adjusting again? Or Replace all cables and remote controller? Do not want to be stranded off shore with babies in tow.

Alldodge, DTR member? Your callsign is familiar.

 

[Bt Doctur]

The interrupter DOES NOT ACTIVATE going into gear, if it does the lower shift cable needs replacing.The interrupter is wired to the negative post of the coil and to ground. when activated, it grounds out the ign .

 

[NHGuy]

When adjusting you put it all the way into gear with the control stick at the helm. If the upper shift cable goes further when you throttle up, (killing engine) you probably didn't have the stick all the way into gear during the adjustment.
You can watch the cables and see how it works. When you move the stick the shift cable moves by itself, then the throttle cable moves.
Follow Achris's video exactly and it will be right. If not you usually need a lower cable.

 

[thegoat86]

I will get into it this weekend. I will take some photos and post them so all can see what I am doing.