# Mercury 15HP 2 Stroke - Electric Start Not Working



## Brett

Make sure the starter bolts attaching it to the block are tight.
If loose the starter may not be fully grounded and blocking full current flow.
Enough ground for the solenoid, but not for the amperage needed for the starter.
And starters do short out, especially in the marine environment.

This link is meant for automotive use, but the process is the same.

http://www.misterfixit.com/starttst.htm


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## cutrunner

Do NOT tap the starter with a hammer!!!!!!!!!!!!!, if you do, chances are your going to need a new one for sure


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## Gramps

Make sure you battery has enough juice, my Merc 25 had the same symptoms after I nearly toasted the battery... The starter was fine, just was not receiving enough power to spin up.


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## fsae99

If you heard the solenoid click check the battery, then check the solenoid, then the starter. If is was kill switch you should not hear anything.

Battery should be up around 12.8 volts, if it is down to near 12 volts or less it needs to be charged or replaced. Try charging first. Assuming all is well.

Solenoid is nothing more than a electromagnetic switch, when current is applied one side is magnetized and "lifts" an internal contact across the battery in and battery out poles completing the positive wire to the starter. 

Take the negative lead from a multi meter and ground it on the motor, take the positive lead and hold it to the energizer wire (small wire that goes to solenoid from starter switch) hit start switch you should read battery voltage.
Assuming all is well.

Take a jumper cable (only use the red side) hook to positive side of battery and the hook to battery+ out pole of solenoid. If starter works then bad solenoid. You MUST NOT touch motor or any metal parts. Once on the water I cut a square out of the top of a plano box to use as a shield to do this to combat a failed solenoid.

If the above did not work then most likely starter is bad.It is really best to remove starter to test.


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## Brett

> Do NOT tap the starter with a hammer!!


Oooops.... :-[ been there done that when all else failed 18 miles offshore.
It was enough to change the position of something in the starter so it would and we got home.
A little r-n-r (remove and replace) took place before the next trip out.

I was raised in the school of "if at first you don't succeed, get a bigger hammer!."


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## Creek Runner

Like every one else has said, check your battery is fully charged, 

Make sure all connections are tight, 

Next jump the starter if it works then replace the solenoid

Do this by taking a small peice of 4-6 gausge wire and  touch it from the battery hot side on the solenoid to the hot post directly on the starter. 

Also if your kill switch was bad it would turn over all day long it just wouldn't fire off, as the kill switch interupts the fire of the enige by shorting out to ground before the coils. (so the starter would work just fine) Now if it were the saftey netural switch you wouldn't hear anything.


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## Dillusion

Thanks guys, I will be troubleshooting this tonight after work if weather permits.


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## Dillusion

Ok guys:

I attached the electric start cables to my deep cycle nice and tightened down with a wrench, no go. Solenoid clicks and no starting. 

I took a jumper cable and hooked it to the positive side, and then touched the positive wires bolt on the engine, still no start.

I then touched it to the other cables screw for a few seconds...then I realized this was the negative post and it sparked so I. Never did that again lol

When I overlooked the wires, I noticed that the ground wire, about four feet down from the engine has some small cuts in it with corrosion leaking out...could this be an issue?


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## Brett

Yes, I'd replace it.
Resistance can be checked for using a volt/ohm meter.


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## Creek Runner

As Brett said replace any wires that are corroded .

Did you take a jumper wire from the hot side of the solenoid (this will be the + wire coming from the battery attaching to the solenoid) to the Starter directly? There is a stud that sticks out of the starter motor that has a wire going from it to the solenoid.

Use a heavy gauge wire 4-6 about a 12" long and jump from the solenoid to the starter, it will arc and throw a spark a little, but the starter should engage. If it doesn't you have a bad starter. Make sure when you do this your kill lanyard is in the off position so the motor doesn't start.


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## Dillusion

I took a 6ga wire and touched the yellow wire post coming from the bottom of the starter to the positive screw on the solenoid but nothing happened.

If the main ground is bad could this still be the cause?


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## Brett

Disconnect the cables from the boat battery.
Grab a set of automotive jumper cables.
Ground the starter to the negative terminal of the battery
connect the red side of the jumper to the positive terminal of the battery
and touch the red jumper to the positive stud to see if it spins.


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## Dillusion

What I think is the positive starter stud underneath it...is very hard to get to, there is no way an alligator clip is fitting down there


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## Brett

Which is why when testing, the starter is removed from the engine
and worked on at the bench...


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## Dillusion

> Disconnect the cables from the boat battery.
> Grab a set of automotive jumper cables.
> Ground the starter to the negative terminal of the battery
> connect the red side of the jumper to the positive terminal of the battery
> and touch the red jumper to the positive stud to see if it spins.



Ok I did this...

I removed the battery cables, connected the negative post on the battery to the negative terminal on the solenoid/post where a bunch of other stuff is grounded.

I then connected the positive side of the battery to a 6ga wire and I touched the positive post on the bottom of the starter...it sparked a few time but nothing happened.

I repeated this three times and nothing happened.


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## Brett

Dead starter. :'(


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## Dillusion

> Dead starter.  :'(


Shucks.

Is this a DIY Fix? I'm qualified if I had a tutorial...

I'm also having trouble finding the replacement starter? Used or new...Cheapest possible ;D


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## Brett

I''ve attempted it, killed a weekend.  

Much easier to take it to a rebuild shop and swap the old one for a rebuilt one.


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## Dillusion

> I''ve attempted it, killed a weekend.
> 
> Much easier to take it to a rebuild shop and swap the old one for a rebuilt one.


I don't mind spending $100 on a used one...

I don't see anything on that website? You can rebuild a starter?  :-?

Does this have to be a marine shop?


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## Brett

Starters, alternators, generators all can be rebuilt-if you have access to internal parts

[media]http://www.youtube.com/watch?v=1N4GZTHCB-0[/media]

[media]http://www.youtube.com/watch?v=MQf5UB59VJc[/media]


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## Creek Runner

As long as the armature isn't shorted to ground, all you might need is to clean the brushes.


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## Dillusion

Seems pretty simple to rebuild one with kit....how do I know if I need a four or two brush?

I found these on iboats: http://www.iboats.com/Mercury-Starter-Repair-Kits/dm/view_id.271574


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## Brett

Disassemble 





No disassemble....Johnny Five alive!


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## Dillusion

> Disassemble
> 
> 
> 
> 
> 
> No disassemble....Johnny Five alive!


Haha i figured that answer was coming...

I found a local shop that will rebuild for around $100 with one week turnaround time...

Found another mom & pop outboard repair that will take a look at it and said it will be around 100$ or so to fix.

I want to avoid paying $100/hr labor though and install/replace myself.

I can start the motor with the pull start without the internal starter connected, right? :-/


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## Gramps

What year is your Merc?

It is not wise to run the motor without the cables connected to a battery.  The electrical system can short out/fry or otherwise damage itself if run disconnected.

It appears a new starter is $150. How bad do you want e-start?


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## cutrunner

> As long as the armature isn't shorted to ground, all you might need is to clean the brushes.


This^


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## Dillusion

What are *brushes*?

Well, I pulled the starter; you guys will love this!

It's looking rough as hell to begin with. Really rusty and corroded.

Heres what I found inside:










One of the magnets in the bottom assembly completely broken off and many of the bolts completely rusted on the bottom of the starter...

To you guys' knowledge; is the inside 'core' salvageable with a rebuild kit?

ETA: Is this what I need? Will this work? http://www.ebay.com/itm/180701389178?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_1067wt_1163

EDIT2: I purchased this last night and it will be here by the end of the week: http://www.ebay.com/itm/Starter-Mercury-Mariner-15EH-25EH-15EL-15ELH-20EL-25E-50-90983A1-5216040?item=350505821992&cmd=ViewItem&_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D5%26po%3DLVI%26ps%3D63%26clkid%3D8919874363699086995

I know its an aftermarket and may be 'cheaper' than the mercury OEM part, but it has a 1 year warranty so I'll take the dive on it.


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## Dillusion

Ok guys I replaced the bad starter with the new one and it works!

Only problem is, it won't engage the flywheel 

It spins and shoots up about halfway and never even hits the flywheel.

If I connect my battery directly and jump the solenoid, it works just fine and the motor starts up.

Could that corroded ground wire be the culprit?


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## Dillusion

I fixed the problem, whoever wired the motor up last switched the wires around since they were both red. I should have verified before.

Works now!


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## cutrunner

Awesome


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