Shift Interrupt causing engine cut out in bit forward and reverse.

[Rake722]

Hi All, recently had the lower shift cable replaced on my 1994 3.0 LX with gen 2 drive.
All worked well for a few trips then got the cut out issue in both F and R.

I have added a video of the shift plate and switch so you see the issue clearly.

Mercruiser shift interrupt stall problem

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does this look like a shift cable adjustment issue ? How can I fix it please ?

thanks in advance

 

[achris]

If the dogs line up, the switch will trip. You can't check it without the engine running...

 

[Rake722]

If the dogs line up, the switch will trip. You can't check it without the engine running...

Thank Chris - will do a check with engine started this evening and post. Last time it just cut out when I put her in reverse.

will post back later

 

[Rick Stephens]

When interrupts kill the motor, usually is something wrong with lower shift cable or the adjustment. Adjustment usually only effects one direction, either forward or reverse. Since you have both happening you should disconnect the lower at the engine and manually manipulate in and out to see if there is any drag.

 

[Rake722]

When interrupts kill the motor, usually is something wrong with lower shift cable or the adjustment. Adjustment usually only effects one direction, either forward or reverse. Since you have both happening you should disconnect the lower at the engine and manually manipulate in and out to see if there is any drag.

I found the cable badly routed and corrected it and there is minimal drag but the problem is still there.

 

[Rick Stephens]

I found the cable badly routed and corrected it and there is minimal drag but the problem is still there.

I would pull the drive and test the cable without the drive, and the shift shoe on the drive by hand. Should be virtually no drag on it if properly setup.

 

[Rake722]

Thanks all. Problem solved by correct adjustment of the shift cable.

6 inches from centre of barrel to eye, 2mm up from bottom of the anchor pin slot.
Mo more cutting out in either forward or reverse

 

[tank1949]

Hi All, recently had the lower shift cable replaced on my 1994 3.0 LX with gen 2 drive.
All worked well for a few trips then got the cut out issue in both F and R.

I have added a video of the shift plate and switch so you see the issue clearly.

Mercruiser shift interrupt stall problem

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

youtube.com

does this look like a shift cable adjustment issue ? How can I fix it please ?

thanks in advance

I believe that checking also requires to be in water with correct RPMs under a load of water pressure. However, I had a MC back in 86 that shops could never get working correctly. Good luck!

 

[Benny67]

I've been having stalling issues on both my alpha ones(twin screw) over the years and drawn this conclusion after scratching my head attempting to solve it.

I was able to just about eliminate stalling after I did this to the shift plate.

The spring that keeps the kill switch centered fatigues causing it to not snap back as fast as it did when it was new. If you follow that guys directions from you tube (the moderator Chrissa from here I believe is his name) and adjust exactly as he says but also either replace the spring or bend it back to give it more snap it will eliminate the stalling.
I was beating my head against the wall because after I adjusted the cable I'd still end up stalling the engines when I needed to maneuver in tight spaces. I sat back and watched as a friend shifted in and out of gear. I noticed that stupid spring sometimes didn't snap back as fast as it should.
I ended up taking the spring out and bending it to give it some more spring along with cleaning the excess crud out of the entire swivel that allowe it to move smoother. That seemed to solve the issue.

 

[Searay205]

If your boats are older vintage late 80's early 90's it could be your shift shaft binding on the shift shaft seal. When you remove your outdrive there is a long rod that goes to the lower half of the outdrive, one end connects to your shift cable with a wheel. a bushing is installed to seal the shaft through the exhaust passage. the old were just brass or bronze with maybe one lip seal and salt and other sediment collected in the "seal" and made it difficult for the shaft to rotate. the new seals are double lip seals and hang in the exhaust passage a little bit. remember your shift interrupter switch is stupid. it feels resistance it rocks and kills ignition thinking it is the dogs in your outdrive. if resistance is caused by a shift shaft binding in the seal then it rocks out to kill ignition which ends up killing engine since killing engine doesn't eliminating the binding like it does for the dogs in the outdrive. I fought this for years until I figured it out. very prevalent in salt water.

 

[Benny67]

If your boats are older vintage late 80's early 90's it could be your shift shaft binding on the shift shaft seal. When you remove your outdrive there is a long rod that goes to the lower half of the outdrive, one end connects to your shift cable with a wheel. a bushing is installed to seal the shaft through the exhaust passage. the old were just brass or bronze with maybe one lip seal and salt and other sediment collected in the "seal" and made it difficult for the shaft to rotate. the new seals are double lip seals and hang in the exhaust passage a little bit. remember your shift interrupter switch is stupid. it feels resistance it rocks and kills ignition thinking it is the dogs in your outdrive. if resistance is caused by a shift shaft binding in the seal then it rocks out to kill ignition which ends up killing engine since killing engine doesn't eliminating the binding like it does for the dogs in the outdrive. I fought this for years until I figured it out. very prevalent in salt water.

This is something I left out in my last post.

The stalling issue only started after I replaced the shift seals. When I did it, I did it to both my drives at the same time.
The seal change introduced the stalling issue because it caused extra resistance in the lower shift cable. This extra resistance caused the kill switch spring to react slower because of the extra resistance created by pushing the shift shaft back and forth over the new and tighter seal.

Gotta say, being able to read others input really helps sort stuff like this out.