Problem with pre-alpha (MC-1) mercruiser 165 -- not starting?

porchlight

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Jul 21, 2018
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47
Hello all,

I'm having some issue with my inboard, and I'm hoping that you all might be able to provide me with a starting point to tracking down the issue.


Everything worked fine about 6 months ago, but things have sat unused since then. Went out to start it up the other day and turned the key, and just got a big ol' click from the solenoid, but the engine didn't turn over.

I figured, maybe low battery, so I charged everything up and went back up, and same thing. Big click, not turning over.

So, to me, this means that I'm getting juice to the solenoid, but for some reason it's not reaching the starter motor. I figured I may as well try to jump the starter motor, but that didn't work either.... of course, I may have been doing something wrong with this step, so I guess I should confirm that I was trying to do this properly.

For reference, here's a shot of the whole engine:
engine.jpg

And the "electrical" area:

electrical.jpg

So, at the bottom there, I thought this was the starter motor. Closeup:

starter.jpg

So you can see the thick red cable leading to the terminal there. I tried to jump straight from the battery to this terminal, but the engine still didn't turn over.

I am confident that I was getting juice to this terminal, because I had the blower running, and when I jumped to this terminal, the blower came back on.

Is this even the starter motor, and if so, is this terminal (with the red cable) the right place to jump it?

I'd also appreciate any other thoughts on how to get it started. Is there anything that would cause the starter to lock up? Some safety feature or similar? I definitely had it in neutral, anything else?

It feels so weird that it would be working fine and then just..... stop working.

Thanks!
 

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Scott Danforth

Grumpy Vintage Moderator still playing with boats
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start by cleaning every connection from the battery to the slave solenoid to the starter, then from the batter to the block ground. by clean, shiny and clean enough to allow your children to eat off of.
 

TyeeMan

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Verify that the engine does in fact turn over, as in it could be hydro locked from failed manifold, riser, or riser gasket.

On my previous boat when riser gasket failed it was a matter of about 1/2 hr. Came off one lake, boat was running like a million bucks, decided to go to another lake a few minutes away. Backed the boat in, hit the key and all I got was a click. I could hear the click of the starter bendix gear engaging but it couldn't turn the engine over as I ultimately had water in 3 cylinders.

In regards to the starter there's an old trick you can try. Smack the side of starter with a hammer. If you have a bad spot on your starter motor armature smacking the starter with a hammer might move the armature enough to get to a good spot allowing you to start the engine.
I've done that twice in my life on previous older trucks. Worked like a charm.
 

kenny nunez

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Get a remote starter button that has the wires with alligator clips from one of the local auto stores. With one wire connected to the large battery connection on the starter and the other wire connected to the yellow wire terminal to the right of the large terminal try pressing the button, if the engine turns over then the boost solenoid that engages the main solenoid is the problem. It looks similar to the one that is on the trim pump and is to the rear of the 2 porcelain resistors on the back side of the engine. If the engine does not turn over remove the spark plugs and see if there is any water or rust on the spark plugs.
What you have there is a 69-70 relic. It needs a lot of cleaning in regards to the rusty terminals. The bad news is some are going to break so start by spraying everything with WD40 or a similar product.
You may just have a starter that needs replacing if everything checks out to be in good order.
 

wahlejim

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+1 on cleaning the terminals. Just looking at those pictures that was my first instinct. Shiny metal makes a huge difference. If you go the hammer route, it doesn't take much. If you have a dead blow, even better. Too mch on the outside can break things inside.
 

porchlight

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Jul 21, 2018
Messages
47
Thank you all for the replies.

@scottdanforth: I took your advice and cleaned everything as best I could... it really needed it, but still no dice on the motor.

@Tyeeman: I tried a deadblow to the starter, but didn't get any change. I was being pretty gentle, but I'm gathering that gentle is better so as not to cause damage? Also curious: What's the best way to ensure that the engine turns over? I guess I just don't want to do anything to cause more damage if things are locked up.

@kennyNunez: I picked up a remote starter and will try that next. And I will also spray with wd-40 :)

BT doctur: The battery cable is, i believe, the red one below the black one your arrow is pointing at. Here's a better shot, it's the red one that runs down away from the starter and then you can see it better as it travels up the transom:
cable.jpg

Thank you all!!
 

Bt Doctur

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Aug 29, 2004
Messages
19,092
If you jump from the main cable to the yellow wire at the solenoid that will spin the starter. double check the negative connection as well. corrosion car show its head there too. If the starter goes crunch, you have a hydro lock condition or something is seized
 

TyeeMan

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If your alternator belt is properly tight you can put a socket/ratchet on the nut on the alternator pulley and likely rotate the engine that way. That's what I did with mine when it hydro locked
You could also put a socket/ratchet on the harmonic balancer nut BUT you do not want to over tighten that.
 

porchlight

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Jul 21, 2018
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@btdoctur: So sorry, but I don't think my solenoid has a yellow wire. I think my photo ended up just being low resolution as it got uploaded... there are a lot of black wires with those yellow terminal connectors on them, which might make it look yellow in the photos! But all of the solenoid wires are black... could I trouble you to point out the wire you're referring to, and I'll try to jump it?

@tyeeMan: Thanks! I will try to jump it first, and if nothing happens, I'll check via the alternator nut.

Will keep you posted!
Thanks again, everyone!
 

porchlight

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Jul 21, 2018
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@btdoctur: thank you, I see. Just for my own information, is that my solenoid or my actual starter motor? I had figured that it was my starter motor, but maybe I'm confused.

thanks!
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
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the starters solenoid is mounted to the starter motor, the slave "relay/solenoid" operates the main solenoid. This is because most boat wiring is to thin a gauge and too far from the key switch so a second low currect relay/solenoid is used to operate the main starter solenoid.
 

porchlight

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Jul 21, 2018
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@btdoctur: I see, thanks! I didn't realize there were two solenoids. Will try jumping it and report back :)
 

porchlight

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Jul 21, 2018
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Hi all,
Finally got a chance to head down and try jumping the cables as suggested by @btdoctur.

I jumped them, and definitely didn't hear a crunch (https://youtu.be/y3ralI_mxQ0). I got the exact same noise as I get when turning the key.... just a big solid click.

It sounds like the solenoid is turning over just fine, but for some reason the starter motor isn't getting any juice. The engine seems like it turns over, so I'm guessing next step is to find the starter motor and give that a look? Does the big click but lack of anything else tell anyone anything?

Thanks everyone!
 

Bt Doctur

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The cable end in the video touching the starers main post is connected where?
 

porchlight

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Jul 21, 2018
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Hi Bt Doctur,

I tried to follow the directions you gave in this diagram:


image-305828.jpg


I took this as, I should jump the main terminal (on the left) and basically follow the green line in order to jump it to the terminal on the right with the yellow wire coming out of it.

You can kind of see it in the video. That orange thing that's blocking a good view of the terminal with the yellow wire is in fact, the other end of my jumper cable :)

thanks!
 

wahlejim

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Just looking at the pictures, it does not look clean enough yet. Get a good wire brush and go to town on all of the connections. I know you mentioned charging the battery, but is it holding a charge? Have the battery load testedif you have a tester or take it to an auto parts store. They will usually test for free as it takes all of 30 seconds from start to finish. You may not be getting the cranking amps necessary to turn the motor.

Before going through all of that though, my first step would be to pull the spark plugs and try turning the engine over. If it turns over and water blows out, we have the problem and can chase mechanical problems over electrical. If it still does not turn over and no water comes out, then its electrical gremlins showing up that can be chased down and eliminated.
 

porchlight

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Jul 21, 2018
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Hi Wahlejim,
Thanks for the reply. Those photos were before it was cleaned, but then I got the advice here to make sure everything is super clean so I took sandpaper to all the connections from the batteries (which are holding a charge, I have a load tester) to the relay to the solenoid.

I guess a next step would be to turn the engine over with the plugs out... I turned it over the other day, and it seemed okay, but I'll do it again and pay extra attention. I also can't hear the starter motor even trying to turn over, so I wonder if something is wrong there.

I was listening for a "crunch" sound when jumping the solenoid, but it just sounded like a big click with no sound from the starter motor at all.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
That sounds like the solenoid is pulling in, but the starter motor is not turning. Pull the starter motor out and check it... Recently had that problem on my car (6.5TD) and it was the plate inside the solenoid. It was pitted badly and not conducting power to the (starter) motor...

Chris.......
 
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