"Manual" Shift interrupter switch, instead off original?

Mk-0

Cadet
Joined
Oct 22, 2008
Messages
14
My engine is a -95 5.7L Bravo = No interrupter switch.
And the drive is a Alpha one..
Planning to install a microswitch on the shift/throttle control, that you simply tap down when the resisting starts to occur, when trying shifting to neutral..
Might a 5.7L v8 have enough momentun, so it could fire up again after the ignition has been off for about 0.2 seconds? (estimated time what takes to hit neutral, without any dilly dallying in the shifting) :)
 

havasuboatman

Ensign
Joined
Mar 5, 2009
Messages
904
Re: "Manual" Shift interrupter switch, instead off original?

5.7L Bravo?
Why don't you just add the shift interupt switch to your remote shift unit where it belongs? It just seems to me like doing it the way the boys at Mercruiser designed it would be simpler all the way around.
 

Mk-0

Cadet
Joined
Oct 22, 2008
Messages
14
Re: "Manual" Shift interrupter switch, instead off original?

5.7L Bravo?
Why don't you just add the shift interupt switch to your remote shift unit where it belongs? It just seems to me like doing it the way the boys at Mercruiser designed it would be simpler all the way around.

pls, no "why" questions, okay?

Just curious to know if the momentum is high enough to restart after a short while?
 

JustJason

Vice Admiral
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Aug 27, 2007
Messages
5,320
Re: "Manual" Shift interrupter switch, instead off original?

Okay then yes it should work. You'll still have to be a bit crafty with your shifting skill for it to work without stressing out the cable.
 

Haut Medoc

Supreme Mariner
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Jun 29, 2004
Messages
10,645
Re: "Manual" Shift interrupter switch, instead off original?

Sounds dangerous to me....
You might as well shut it off every time you want to take it out of gear....:rolleyes:
 

jaxnjil

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Aug 3, 2007
Messages
1,368
Re: "Manual" Shift interrupter switch, instead off original?

pls, no "why" questions, okay?

Just curious to know if the momentum is high enough to restart after a short while?



your going to have to install a alpha shift plate in place of your bravo and thats where the switch is any way. why not do it right and be done.
as HAUT stated

"Sounds dangerous to me....
You might as well shut it off every time you want to take it out of gear"

in close quartes i can see you killing the motor or not getting your shift made
 

lowkee

Lieutenant Commander
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Dec 13, 2008
Messages
1,890
Re: "Manual" Shift interrupter switch, instead off original?

So long as your engine is still spinning faster or as fast as the starter turns it, you will be fine.

Keep in mind, you are asking people to give advice on something that could be really unsafe, both in terms of engine wear, drive wear and cable stretch, but also in terms of possible stalling when engine/shift control is most needed (avoiding a collision). Frankly, not asking why would be a little irresponsible and jimmy rigging something so crucial is as well. I hate that stupid switch as well, but it exists and is needed, so it needs to be there. Sure, there is likely a 'sweet spot' in the shift where it could go, but shift cables stretch, and one day that sweet spot will move.. what will be happening when it does? I hope not a near collision..

When working on your Frankenstein, don't forget your mad scientist laugh. "Muahahahahahah!" ;)
 

Mk-0

Cadet
Joined
Oct 22, 2008
Messages
14
Re: "Manual" Shift interrupter switch, instead off original?

Okay then yes it should work. You'll still have to be a bit crafty with your shifting skill for it to work without stressing out the cable.

"Practice makes perfect" :)



Sounds dangerous to me....
You might as well shut it off every time you want to take it out of gear....:rolleyes:

I have a 16ft race boat where i have pulled out the safety switches, so i can start the engine in forward or reverse (propeller with a alloy hub tears to mutch on the gear teeth, when shifting in the conventional way..)
installed a start and stop push buttons on the shift control, besides the trim switch, and throttle is controlled with a gas pedal.
for the last two years i have never had any dangerous situations with this one, when docking etc, so seriously i dont think i will have any problems operating a cut out switch at the same time when shifting..

You just gotta know what you are dealing with.

your going to have to install a alpha shift plate in place of your bravo and thats where the switch is any way. why not do it right and be done.

A: I dont have a Alpha shift plate.
B: The boat will be set in water on the following weekend
C: in my opinion it doesent mather in what way you will get the pressure eased from the gears, without stalling offcourse.


So long as your engine is still spinning faster or as fast as the starter turns it, you will be fine.

Ok.

Keep in mind, you are asking people to give advice on something that could be really unsafe, both in terms of engine wear, drive wear and cable stretch, but also in terms of possible stalling when engine/shift control is most needed (avoiding a collision).
Frankly, not asking why would be a little irresponsible and jimmy rigging something so crucial is as well. I hate that stupid switch as well, but it exists and is needed, so it needs to be there.

My answer to Haut might give you an idea what experiense i have of this kind of stuff.
Excessive engine wear is nothing to be worried about in this case, and the alpha one drive works just fine without the cut out switch, also without any worries of excessive wear.
Know a couple of daycruisers with alpha drive and warious types of 4cyl car diesel engines (Mitsubishi &Toyota etc, tuned up between 120-170bhp) and the shift cut-out system has been deactivated in both cases, cause at idle they run pretty rough compared to a 6 or 8 cyl engine, so they simply do not need any devices that would ease constant gear pressure in the drive.


Sure, there is likely a 'sweet spot' in the shift where it could go, but shift cables stretch, and one day that sweet spot will move.. what will be happening when it does? I hope not a near collision..

I think the shift cable wont stretch so long i do not have to operate the shift control with brutal force.

When working on your Frankenstein, don't forget your mad scientist laugh. "Muahahahahahah!" ;)

Others may do what they can, but i do what i want;)
 

Don S

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Re: "Manual" Shift interrupter switch, instead off original?

I have a 16ft race boat where i have pulled out the safety switches, so i can start the engine in forward or reverse

The shift interrupt system is not a safety switch, it's designed to allow the drive to come out of gear without messing up the shift cable, the conrol, or the shift dogs by having to force it. Since this is done only when comeing out of gear I really don't understand the concept of what and why of what you are doing.

Others may do what they can, but i do what i want
Then I would suggest you just do what you want and not ask a bunch of strange questions you don't want to listen to the ansers on.
 

180shabah

Rear Admiral
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Mar 26, 2005
Messages
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Re: "Manual" Shift interrupter switch, instead off original?

Others may do what they can, but i do what i want

So why bother seeking mutual consent?
 

gadget73

Petty Officer 1st Class
Joined
Jun 20, 2009
Messages
308
Re: "Manual" Shift interrupter switch, instead off original?

well, functionally you'll be doing exactly the same thing the stock setup does. It simply shorts out the ignition system to cut spark for that split second. I see no valid reaason why doing it manually would be any different than having the shift plate do it. Getting your motions down to make it happen will take some effort though. Personally I can't stand that stock interruptor thing, and given the headaches they have caused me over the years I'm not so opposed to trying to do something different.
 

Don S

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Re: "Manual" Shift interrupter switch, instead off original?

Personally I can't stand that stock interruptor thing, and given the headaches they have caused me over the years I'm not so opposed to trying to do something different.

You would be surprised how easily and well they work, when you use OEM parts (I really hate all the aftermarket cables, they are junk) and set it up by the OEM manual and you get years of trouble free service from them.
 

Mk-0

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Joined
Oct 22, 2008
Messages
14
Re: "Manual" Shift interrupter switch, instead off original?

The shift interrupt system is not a safety switch, it's designed to allow the drive to come out of gear without messing up the shift cable, the conrol, or the shift dogs by having to force it. Since this is done only when comeing out of gear I really don't understand the concept of what and why of what you are doing.

Just wanted to explain that i'm used to operate some extra buttons when shifting and docking..


Then I would suggest you just do what you want and not ask a bunch of strange questions you don't want to listen to the ansers on.

My basic question was that does the 5.7 litre bravo have enough momentum at idle* to fire up again after the ignition have been off for a couple tenth's of a second?

*forgot to mention this in my first post.

But youre right, i shouldn't have wrote the reason itself for my question.
in that way "Why?" "Do this" "do that" topic responses would have stayed in the minimum..
 

Don S

Honorary Moderator Emeritus
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Re: "Manual" Shift interrupter switch, instead off original?

Cant stand a joke?
Or did i hit a soft spot?;)


Since it's all a joke, moving to the appropiate forum.
 

Mk-0

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Joined
Oct 22, 2008
Messages
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Re: "Manual" Shift interrupter switch, instead off original?

Since it's all a joke, moving to the appropiate forum.

No offense, but do you really think that this is the correct way to be treaten, when someone is trying to solve a common problem by a alternative method?
what a real mature act of you.
 

Maclin

Admiral
Joined
May 27, 2007
Messages
6,761
Re: "Manual" Shift interrupter switch, instead off original?

Run the idle up some since no OEM controls are in place. Then just hit your add-in kill switch intermittently to control the idle if needed.
 

ringmaster72

Petty Officer 2nd Class
Joined
Oct 1, 2007
Messages
102
Re: "Manual" Shift interrupter switch, instead off original?

LOL, there does seem to be a lot of attitude on these forums, especially if you are not in the narrow confines of what is "right" for a marine application.

I am in a similar situation as you, I have been running mine without a switch for 2 years now and have not had any problems. I just shut it off when I want to change directions. It is a pain and I am going to eventually hook it up, but I have not gotten around to it. I put an older 350 in place of a 90 4.3 and it has a different ignition so I never got around to hooking it up right.
 

IVAZ

Master Chief Petty Officer
Joined
Jan 6, 2009
Messages
816
Re: "Manual" Shift interrupter switch, instead off original?

No offense, but do you really think that this is the correct way to be treaten, when someone is trying to solve a common problem by a alternative method?
what a real mature act of you.

The forum you posted your question on is for repair not jerry rigging.
Why not buy the correct parts instead of mickey mousing your boat?
 

cadunkle

Petty Officer 2nd Class
Joined
May 8, 2006
Messages
128
Re: "Manual" Shift interrupter switch, instead off original?

The forum you posted your question on is for repair not jerry rigging.
Why not buy the correct parts instead of mickey mousing your boat?

Don't sweat these guys blowing smoke. They insist they are right all the time, and bash anyone not in their narrow view of what is right or acceptable. They love to be rude and bitter in their responses to new people on the forum, and bicker with one liners to pad their post count, in an attempt to validate their bitter responses and "extensive knowledge". They typically throw out either "bah, marine application blah blah stock factory blah" or "need more info, blah blah, vessel length, deadrise, blah blah, oh, yes of course that engine you mentioned in the first post will only require 87 octane". Humorously, whenever I post a question with detailed information about my boat, engine, etc. and what I've already diagnosed and tried for a solution, I get no repsonses from the post *****s.

I see no reason why your idea won't work. I also see no reason to do it that way. Personally I would just get the appropriate bracket and hardware to make the Alpha drive work, or better yet go back to a Bravo. Merc provided a system that works automatically and required minimal maintenance. I don't know of any better ways. if you have too much cam for a Alpha drive you have no option except to start in gear so the point is moot, but if not the case just use the interruptor switch. It's simple and it works.
 
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