79 mercruiser 260hp engine smooth shift switch

knightowl

Petty Officer 2nd Class
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Sep 20, 2008
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had a question. I spent about a day lining up the two cables to work right with the "aka kill switch" . I got it fine tune where if i would hit forward; the shift arm would pull the kill switch arm to its correct direction. When i shift to neutral the arm moves to center like it should and when i shift to reverse i finally got it tune where the arm moves to reverse and trigger the kill switch.

Heres the problem. What the heck was the point if all it does is kills my engine instead of killing it for 1 second while shifting(for smooth low RPM shift). instead its kill my whole engine. em i missing something or are their more wires needed to be connected because one grounded and other to negative coil. Do i need some kind of spring to pull the arm back into the meddle point so it wouldn't hold the killer switch ? If i did that i dont think my weak cables would have the power to move the arm at all... (this setup is by far not very bright)

Im starting to think im missing some parts or something. I do have the big "V" spring under my shifting arm although it is loose but if i adjust it then my cables can't move my arm at all... I have the worlds stupidest setup in my opinion. Its the control leveler arm that has the two cables running from the same way instead of each side.

Please help me out if you can, i have the shifting figured out to the point where i can shift all 3 ways if i disconnect the smooth kill shift switch with the little rubber wheel on it .........but if its connected it kills my engine during shift. If you want pictures, i would gladly provide it, thanks ahead of time!
 

Alumarine

Captain
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Feb 22, 2005
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Re: 79 mercruiser 260hp engine smooth shift switch

I believe it should be adjusted so it momentarily kills the engine when you shift OUT of forward or reverse.
 

Don S

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Re: 79 mercruiser 260hp engine smooth shift switch

I think your biggest problem is adjusting it without really understanding what it does. It's not a "Smooth Shift Switch", it's a shift interrupt switch (also NOT a kill switch) and shouldn't do anything when going into gear, and if on muffs it won't come into use either. Only when in the water is there enough pressure on the reverse cut shift dogs to cause the shift interrupt system to work, and as soon as it comes out of gear, it releases. Split second job.

My guess, is you need a new lower shift cable because yours is corroded and stiff operating. Plus you need the OEM manual to study and learn how to adjust it properly. Here's a link to the manual, it's about 301 MB so give it time to load and save to your computer.

http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/04/cover.pdf
 

knightowl

Petty Officer 2nd Class
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Sep 20, 2008
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Re: 79 mercruiser 260hp engine smooth shift switch

I believe it should be adjusted so it momentarily kills the engine when you shift OUT of forward or reverse.

I think thats physically impossible since i have the arm with only "1" indent in it so i can only be setup for 1 gear. ....and it still doesnt make any sense because the engine would never start as the interrupter is always activated.

Heres my setup. (pic attached)

------------------------------
reply two:

whats the cable have to do with it really? I mean if i have no problems shifting and i got it adjusted by the book and i have the arm move back/forth and the switch moves from the center of the arm to the edges back and forth, how is that the cables fault? Is the cable suppose to "un-trigger" the moving arm back into neutral zone magically? Just makes no sense to me. We know the interrupter switch also works because it kills the engine.

The manual didn't say anything about having it under water for the interrupter switch to work properly. Will the pressure force the cables to back-track the arm into neutral zone so the switch wouldn't be trigger any more? Just cant get the concept down. By fair the dumbest thing mercruiser could of ever engineered. Seems like everyone is having this problem..

Can it damage my outboard and gears if i just dont connect the interrupter switch since the whole shifting mechanism is a joke? I got a brand new engine with outboard installed. Thanks for replys fellas.
 

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Don S

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Re: 79 mercruiser 260hp engine smooth shift switch

Can it damage my outboard and gears if i just dont connect the interrupter switch since the whole shifting mechanism is a joke?

You will damage something, not sure if you will pull the cable apart or round over the shift dogs in the drive. The reason for the shift interrupt system is to make the engine hesitate slightly under load so the reverse cut shift dogs will let go.
When your engine is running on muffs, there is no load the shift Y bracket shouldn't even move without a load. If it does, that means the cable or the shift mechanism in the bellhousing or the outdrive is binding. About 99% of the times it's the shift cable itself causing the problem. This is a VERY COMMON problem on Alpha and pre-Alpha drives.
 

knightowl

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Re: 79 mercruiser 260hp engine smooth shift switch

You will damage something, not sure if you will pull the cable apart or round over the shift dogs in the drive. The reason for the shift interrupt system is to make the engine hesitate slightly under load so the reverse cut shift dogs will let go.
When your engine is running on muffs, there is no load the shift Y bracket shouldn't even move without a load. If it does, that means the cable or the shift mechanism in the bellhousing or the outdrive is binding. About 99% of the times it's the shift cable itself causing the problem. This is a VERY COMMON problem on Alpha and pre-Alpha drives.

Don i think you might be correct after all. If you say that the Y bracket is only supposed to move when boat is UNDER WATER ONLY NOT ON MUFFINS then i see your point because when i aligned my 2 cables by the book the Y bracket barely moved if any at all when i tried putting it in either gear. I had to tune it just a bit to get it to work both ways.

But i did notice that my cable does have some "plastic covering cracks" and i do notice that if i move my cable from side to side it moves the Y bracket so seems like my cable needs changing.

I will buy a brand new throttle cable and replace it. Should i replace the outboard cable too? Then when i do the test so i take it out to the water and test it after i tune it by the book?

Also on the Y bracket, their is a "V" spring in the meddle. How much force should that spring push back? I dont want the cables to be over working yet i want to make sure the spring actually works. If i move the Y bracket to either side should the "V" spring underneath be touching both sides no matter which way the Y bracket moves?

Thanks a bunch buddy for youre time! Keep the good stuff coming!:)
 

Bondo

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Re: 79 mercruiser 260hp engine smooth shift switch

Don i think you might be correct after all.

Ayuh,..... Once again,..... ;)

If you go back,+ Reread the responces from Don,...
He's already answered the questions you're asking Now....

Btw,...
I don't think you need a Throttle Cable,.. It's usually the Lower Shift Cable.....
And Don already said that anyways......:D
 

knightowl

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Re: 79 mercruiser 260hp engine smooth shift switch

Ayuh,..... Once again,..... ;)

If you go back,+ Reread the responces from Don,...
He's already answered the questions you're asking Now....

Btw,...
I don't think you need a Throttle Cable,.. It's usually the Lower Shift Cable.....
And Don already said that anyways......:D

so the lower shift cable is the cable that runs to the outboard drive right? its usually like 2-3 ft max? Its the one that has a bracket with a hole in it and it drops into a studded threaded bolt.
 

JustJason

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Re: 79 mercruiser 260hp engine smooth shift switch

that's the one.
You need to pull your drive to change it.
 

knightowl

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Re: 79 mercruiser 260hp engine smooth shift switch

that's the one.
You need to pull your drive to change it.

I just checked the dealer paperwork and checked the cable for myself. It the cable looks brand new so i checked the paperwork and they did install me a new shift cable... Its the throttle im worried about.

Now back to the shift switch. Im taking the boat out tomorrow, how should i adjust my cable as of right now. Just 6" from the meddle of the bolt hole to the meddle of the metal stud while the GEAR is FORWARD and the shift cable is all the way in?

Next for the throttle cable. Fully shifted forwarded still, I just adjust the moving stud nut until it fits into its stud bolt. Then i pull it out and loop it back 4 times away end of cable.

----
Switch.... If i test it on muffs, should the Y bracket move back and forth when changing gears? Or should it be pretty much be still as im not in water and no pressure is applied? Thanks.
 

JustJason

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Re: 79 mercruiser 260hp engine smooth shift switch

knightowl said:
It the cable looks brand new so i checked the paperwork and they did install me a new shift cable...

doesn't mean it was installed correctly.

If you paid somebody to fix your shifting, and your still having issues, then take it back.
 

knightowl

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Re: 79 mercruiser 260hp engine smooth shift switch

I understand, but when the boat is on muffs and i shift is the Y bracket required to move to SIDE TO SIDE When shifting forward, n , reverse?
 

JustJason

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Re: 79 mercruiser 260hp engine smooth shift switch

nope, not on muffs
on the water
 

knightowl

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Re: 79 mercruiser 260hp engine smooth shift switch

So i tested the boat today in water. Great news and bad news.......... When i shift from NEUTRAL to FORWARD the Y bracket DOESN'T move. When i shift from FORWARD to NEUTRAL the brack DOES move and the engine dies for a split second but then recovers no problem.

Same thing with reverse gear. When i shift from neutral to reverse the Y bracket doesn't move and the engine doesn't lose RMP. But as soon as i switch back INTO neutral from Reverse or forward the Y bracket works flawless and activates the switch which causes the switch to work for a split second and then the engine recovers no problem..


So my question is whats going on? Isn't the Y bracket suppose to move when SHIFTING INTO GEAR instead of shifting OUT of gear??

I have the outdrive cable adjusted 6" from the center of the bolt hole to the center of the square stud. Then once i place the outdrive cable to its slot spot, i adjust and drop the other cable into the bolted stud.

Why is it shifting weird? At least i have all the gears now :)

....Another bad thing... I cant go fast on the boat anymore, as soon as i start picking up speed it feels like my propeller skips or something happens where it seems like the GEARS are slipping or propeller is slipping but the engine keeps screaming but the boat not moving any faster (just maintains speed). I check the propeller and it moves back and fort so im gonna try to tighten the main bolt and make sure the lock washer is nice and tight..It was so lose that my lock washer from the main bolt was loose.. You think that could have been the problem?

Sorry for all the text fellas! I appreciate your hard work and you're time! :)
 

JustJason

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Re: 79 mercruiser 260hp engine smooth shift switch

sounds like your shifter is working the way it's supposed to now.

knightowl said:
So my question is whats going on? Isn't the Y bracket suppose to move when SHIFTING INTO GEAR instead of shifting OUT of gear??

nope...
the teeth on the clutch and gears are undercut. so as soon as they touch they pull themselves together. in order to get them apart, you need to take the load off them (cutting the engine)


as to your second problem. sounds like you either have a spin prop hub or a spun engine coupler.
you may want to start a new thread on the new topic.
 

waterone1@aol.com

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Re: 79 mercruiser 260hp engine smooth shift switch

OK, we can now move past the shift interupt switch. When a boat isn't gaining speed, yet the engine rpm's are racing, one of three things are happening : the drive isn't all the way down, and the propeller is "cavitating", the prop has some sort of hub that is slipping or there is a engine coupler that is shot and slipping.
 

180shabah

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Re: 79 mercruiser 260hp engine smooth shift switch

WOW, I think my blood pressure went up 10 point just reading this thread...

knightowl, calm down, there is a very steep learning curve when it comes to boats. Not that they are incredibly difficult or comlplex, but half of what you know about cars, does not apply even though you are running a 350 chevy. It can be frustrating at first, but the members of this forum will get you over the hump as long as you are willing to listen and provide information as requested.

If you think the very simple shift interrupt system is the dumbest thing you've ever seen, then you have lived a very privilaged life indeed. Talk to someone who has ever had ESA problems on a cobra drive and ask how they feel about you $2 switch that can be replaced in just a coulpe of minutes IF it ever goes bad.

Also, like Jason said above, your high RPM/low speed issue needs to be addressed in a new thread otherwise it will just get burried in this one.
 

knightowl

Petty Officer 2nd Class
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Sep 20, 2008
Messages
111
Re: 79 mercruiser 260hp engine smooth shift switch

ask how they feel about you $2 switch that can be replaced in just a coulpe of minutes IF it ever goes bad.

actually its more like $175 bucks since if i ever want to replace the switch i have to go through east coast since portland or, or seattle wa, doesnt stock the switch i have... So yeah, nice try but my switch WAS bad i took it apart and fixed it. :D
 
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