1976 omc 175 stringerdrive 800 electric shift issue

TonyCast

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Feb 25, 2014
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I've been an avid reader of this forum and have found it very helpful so far. However this is my first post and im in need of some help here from the omc gurus. Bear with me.

I have a 1976 OMC 800 stringerdrive 175HP powered by a ford 302. It is an electric shift drive. This engine and drive has been performing great and shifting smoothly into and out of forward, neutral, and reverse until recently. I noticed last time I took it out the reverse was kinda finicky while engaging. It would not engage right. It would rev up in reverse and then bang into the reverse gear(not smooth). Then yesterday I took the boat out and launched it. Reverse acted up again backing off the trailer. Then to the new problem:

When I put it into the forward gear to leave the marina, the control was very stiff to push forward and would not engage the gear at all. So then I shut the engine off (still at the dock) and tried to restart the boat and nothing..... It would not start or crank. I do have power to everything. It just acted as if it wasn't in neutral (which it was). Im baffled as to what failed. I pulled the control to check the switch inside and it will not click forward at all. Like it's jammed. However the switch clicks from neutral to reverse but in the neutal position the engine will not crank over.

There is two connections at the control in the helm. One is my throttle cable to the carburetor, and the other is the switch. Which I believe is broke and needs replacement. (I think this switch is also my electric shift that sends the power back to the coils?)... Can someone chime in and let me know if im on the right track here. I hope my explanation is clear and makes sense.

* the drive was just serviced and has new clean "type C" oil in it. And the waterpump housing and impeller are brand new. The last 5 trips the boat ran flawlessly. How do I get it back into neutral?

Need some help here guys!!! Thanks.
 

Redrig

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Oct 13, 2009
Messages
871
Re: 1976 omc 175 stringerdrive 800 electric shift issue

weclome . And yes , it sounds like you are on the right track , sounds like controller issues . I would not mess around with that controller anymore until its fixed. You dont want to have that bad controller send 12v to both F and R at the same time and really mess things up. That will be an expensive fix . unhook the blue and green shift wires for the outdrive , they are back by the tilt motor in the bilge area. That way you dont damage anything on the outdrive and can focus on the shifter.

I beleive too there is a way that you can bypass the nuetral safety swtch. Someone else can chime in on specifics, I know on my controller I have 5 wires from the controller. But there really is no nuetral on the drive , nuetral is just when there is no power going to the outdrive in either F or R, it sounds like you cant get a start because your switch is broken and the controller "thinks" its engaged.

Those switches are ridiculously expensive to replace and there are a few styles out there, some peeps on here have used a type of drum switch rather than replacing what was there.

Good luck with the fix
 
Last edited:

TonyCast

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Re: 1976 omc 175 stringerdrive 800 electric shift issue

Thanks for that info. Any idea on where to get a "drum" switch? It is something worth considering if it functions the same.

Now when I disconnect the wires to the switch near the tilt motor, can I then test the gears by applying 12v to each wire one at a time, then trying to spin the prop and see if there is resistance?. It would be nice to eliminate the coils before purchasing a new switch.... U know what I mean?

So are you saying a failed switch in the control would make the controller hard to push and throttle up or get into gear? Or cause the gears to be finicky engaging?

Thanks for putting up with my questions!

But yea, it looks, and seems like it would just be a failed switch in the control. Anybody else who wants to chime in plz do. All help and feedback is much appreciated
 

Redrig

Master Chief Petty Officer
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Oct 13, 2009
Messages
871
Re: 1976 omc 175 stringerdrive 800 electric shift issue

yes you can throw 12v to each of the shift wires individually to make sure they are engaging.
 

TonyCast

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Feb 25, 2014
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Re: 1976 omc 175 stringerdrive 800 electric shift issue

yes you can throw 12v to each of the shift wires individually to make sure they are engaging.

Thank you REDRIG for your help. I will try that and post back with what I discover. I asked this same question over on the hull truth forum and someone told me that this drive is not a 400 or 800 series, but an electric shift drive.... ? I've never heard that before.
 

southkogs

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Re: 1976 omc 175 stringerdrive 800 electric shift issue

That's correct; it's not a 400 or 800. Those were designations used later on the hydro-mechanical and mechanical shifts. You've got a plain ole' electric shift ;)

One thing to double check too - do you have Type C lube in your lower unit? In the upper it doesn't matter much, but in the lower the Type C is important to make sure the coils energize correctly.

I dunno' why the failed switch would make the throttle more stiff. Have you checked to make sure your cable hasn't shifted or kinked?
 

TonyCast

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Feb 25, 2014
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Re: 1976 omc 175 stringerdrive 800 electric shift issue

That's correct; it's not a 400 or 800. Those were designations used later on the hydro-mechanical and mechanical shifts. You've got a plain ole' electric shift ;)

One thing to double check too - do you have Type C lube in your lower unit? In the upper it doesn't matter much, but in the lower the Type C is important to make sure the coils energize correctly.

I dunno' why the failed switch would make the throttle more stiff. Have you checked to make sure your cable hasn't shifted or kinked?

I think something inside the switch broke causing it to jam up, therefore causing the throttle to become stiff. So can you tell me where the cable might be? I don't see any cable anywhere other than my throttle cable, but that goes to the carb. Hmmm. I dunno.
And yes, I do have type C oil in both the upper and lower units. Just serviced it with new oil last month.
 

southkogs

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Re: 1976 omc 175 stringerdrive 800 electric shift issue

That's correct: The only cable is running back to the throttle. The electric switch just energizes. That cable actually twisted a little on my boat causing it to stiffen up a bit.

I didn't realize that switch could cause the controller to stiffen - I would have looked at the tension adjustment on it (depending on which controller you have).
 

dlogiacco

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Jul 6, 2014
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I have a true course steering gears can I use another drive that is set up using a push/pull rod
 

southkogs

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Welcome aboard dlogiacco: Better to start a new thread with your question. You'll usually get better results. You'll have to look at the drive itself, or see if you can swap your upper on to the new lower: There's a gear at the front of the uppers that use TrueCourse that may not be there on the ole' push-rod types. I'm not sure what that gear is called off the top of my head as I have the push rod type. One of my spare uppers has the gear, but the one currently on the boat doesn't.
 

markboutros

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Jul 12, 2012
Messages
36
i have a 77 omc stringer drive same thing happen to me, turns out the upper unit siezed, which inturn wont let the engine crank
 
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