25 Merc electric won"t turn over

goblerblaster

Petty Officer 2nd Class
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Dec 26, 2011
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176
I have an 87 model 25 hp merc, 2 stroke electric start that will not turn over, or barely will sometimes. I have put on a new starter, new solenoid, and new battery that is fully charged. When I hit the start button, I hear the solenoid click and sometimes the motor will torn over a couple of times and then stop. I can use the rope start to move the flywheel by slowly pulling the rope, and then hit the starter and it will MAYBE turn over another time or two. I know the starter , solenoid and battery are good. SOmeone told me that if the compression was bad, the engine won't turn over,and maybe something about valves??

Any ideas or suggestions would be appreciated.

Oh, when I start it by rope pulling, the motor runs fine, idles fine, does not miss, seems to have plenty of power, no hesitation, etc.
 

jbjennings

Captain
Joined
Jul 18, 2007
Messages
3,903
Re: 25 Merc electric won"t turn over

If it runs fine and idles good, and starts with the rope starter, then you either have a bad connection or a bad starter. How do you know the starter is good? Don't think there can't be bad NEW parts.
Probably not what you wanted to hear.......:redface:
JMO,
JBJ
 

Peter16

Petty Officer 3rd Class
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Sep 6, 2011
Messages
78
Re: 25 Merc electric won"t turn over

put some jumper leads straight to the starter and see if it turns over fine then.
 

goblerblaster

Petty Officer 2nd Class
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Messages
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Re: 25 Merc electric won"t turn over

If it runs fine and idles good, and starts with the rope starter, then you either have a bad connection or a bad starter. How do you know the starter is good? Don't think there can't be bad NEW parts.
Probably not what you wanted to hear.......:redface:
JMO,
JBJ

I have actually nput 2 starters and 2 solenoids on it. After the first new ones it started OK for about a year then started not working. I put anothr new starter on and it barely turns it over. These were new starters and solenoids notnused or rebiulds. I have taken the starter to Autozone and it tested OK. I have used jumper cables to go straight from the battery to the starter leads, but it does the same thing- won't turn it over.

I'm at the end of my rope !! Well, actually I guess the pull rope is where I am.

Thanks
 

canoemang

Petty Officer 1st Class
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Apr 9, 2011
Messages
350
Re: 25 Merc electric won"t turn over

You got a short or a bad ground.. or grounded short.. if it tests good at the parts store (not connected) but as soon as you connect it back to the Merc it acts up again. You have to go through the wiring and look at all the connections..
 

cyclops2

Banned
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Apr 19, 2011
Messages
1,237
Re: 25 Merc electric won"t turn over

If it did not crank fast on jumpers ??

WEAK battery.

Starter burned out FROM THE WEAK BATTERY. Been there done that 2X with a battery that ran down from pumping out rain water.
9.9 & 30 hp motors do not put out enough power. OR they keep putting out full power when you do high speeds. That OVERCHARGES a battery very quickly. That also weakens the battery causing low voltage & high current into the starter.

Measure battery voltage WHILE cranking. It must not drop more than a 1/4 to 1/2 a volt if fully charged. If it does drop. Pull it out & take it to a auto place for a ...........load test..........

Good luck
 

jbjennings

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Jul 18, 2007
Messages
3,903
Re: 25 Merc electric won"t turn over

If it's one of those crappy CHinese ebay starters, that could EASILY be the problem. Otherwise, I'd say cyclops has it right.
If you're jumping the starter straight from the battery with the proper gauge wires and it's not turning it over good, then the only possibility I can think of would be a bad starter or bad battery.
Wish I could be of more help,
jbJ
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,926
Re: 25 Merc electric won"t turn over

First step in diagnosing ANY motor problems is a compression and a spark test.
Profile,location?You might be close to someone who can help.
Auto zone or any auto parts store will sell loan you tools.Harbor Freight is a good place to get an economical tester.
This item along with sparkies should be in any boaters toolbox.
Remove the plugs.Install tester,jump the solenoid.Let it spin till it stops going up.Then repeat on the other cylinder.
Post the results.J
 

goblerblaster

Petty Officer 2nd Class
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Messages
176
Re: 25 Merc electric won"t turn over

That is my problem. I can't get it to turn over to do a compression check. I can take jumper cables and go black to ground- on one of the bolts that holds the starter on the block, and red to the hot side of the solenoid and the starter does not spin. I am getting voltage across the solenoid and can hear it click when I hit the starter button with no jumper cables.

I can take the starter off and hook it up to jumber cables and i turns like is suppoosed to. Had it checked at Autozone and they said it was OK. If it was burned out, would it turn at all when hooked staight to jumper cables?

The compression must be OK coz it runs fine when rope started. I/m at a loss on what to do next. Can a starter just get too weak to turn the engine over if it works when notg hooked to the engine?
 

jbjennings

Captain
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Jul 18, 2007
Messages
3,903
Re: 25 Merc electric won"t turn over

That is my problem. I can't get it to turn over to do a compression check. I can take jumper cables and go black to ground- on one of the bolts that holds the starter on the block, and red to the hot side of the solenoid and the starter does not spin. I am getting voltage across the solenoid and can hear it click when I hit the starter button with no jumper cables.

I can take the starter off and hook it up to jumber cables and i turns like is suppoosed to. Had it checked at Autozone and they said it was OK. If it was burned out, would it turn at all when hooked staight to jumper cables?

The compression must be OK coz it runs fine when rope started. I/m at a loss on what to do next. Can a starter just get too weak to turn the engine over if it works when notg hooked to the engine?

I don't know why you need to check the compression when you've already said the motor runs good and idles good. Your only problem is the electric start isn't working properly. The starter can definitely be bad and turn over great under no load, and not crank the motor. Keep in mind who is testing the starter at autozone. Either take the starter apart and check the brushes and springs on the brushes, or take it to a starter/alternator repair shop and have them test it after you describe your problem. If you jump the starter directly from a GOOD battery, and it doesn't turn over the motor good, then the problem is the starter.
 

goblerblaster

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Re: 25 Merc electric won"t turn over

I don't know why you need to check the compression when you've already said the motor runs good and idles good. Your only problem is the electric start isn't working properly. The starter can definitely be bad and turn over great under no load, and not crank the motor. Keep in mind who is testing the starter at autozone. Either take the starter apart and check the brushes and springs on the brushes, or take it to a starter/alternator repair shop and have them test it after you describe your problem. If you jump the starter directly from a GOOD battery, and it doesn't turn over the motor good, then the problem is the starter.


Thats what I am thinking, but I have two starters, both from Merc, and they both do the same thing. The battery is new and good.
 

Silvertip

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Re: 25 Merc electric won"t turn over

You are not jumping the system as you were told. Jumping from the positive battery terminal to hot side (battery side) of the solenoid is no different than having the standard battery cable connected. You proved nothing. You need to run that positive jumper directly to the starter or at least to the STARTER side of the solenoid. The engine will spin without the key. If it does, fix the solenoid connections, the battery cable or replace the solenoid as required. And make sure both battery cable ends are squeaky clean and tight. And make sure you check and clean BOTH ends of both cables.
 

goblerblaster

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Re: 25 Merc electric won"t turn over

You are not jumping the system as you were told. Jumping from the positive battery terminal to hot side (battery side) of the solenoid is no different than having the standard battery cable connected. You proved nothing. You need to run that positive jumper directly to the starter or at least to the STARTER side of the solenoid. The engine will spin without the key. If it does, fix the solenoid connections, the battery cable or replace the solenoid as required. And make sure both battery cable ends are squeaky clean and tight. And make sure you check and clean BOTH ends of both cables.

I have put the hot jumper from the battery to the starter side of the solenoid and negative from battery to the bolt that mounts the starter to the block-and no result. I can't get the jumper cable to the bottom of the starter where the wire from the solenoid attaches because there is not enough room. i took the starter off and hooked up the jumper cables and it nearly flew out of my hand it was spinning so fast !! I am going to test the wire that goes from the solenoid to the starter as that is the only reason I can figure that it should not be working. Thanks for the advise. Do you think the starter should spin off the motor and not turn it over? I know this starter has not been used to start the motor more than a dozen times.
 

Silvertip

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Re: 25 Merc electric won"t turn over

If the starter runs normally off the motor but not when installed, then you are either installing it wrong (somehow twisting the housing so it is binding) or there is a wiring issue. If the ground jumper happens to be on a painted bolt, you do not have a good connectioni. It needs to have a resistance free connection to the engine block -- anywhere on the engine block. Since you are connecting jumper cables to the battery clamps and not directly on the battery posts, you need to make sure those battery cable clamps are clean and tight. At the solenoid, remove the cable that runs from the starter to the solenoid. Now connect the positive jumper directly to that cable. If the starter runs, fix/replace the cable. If it doesn't, the starter is being bound up or something is changing with it when being mounted. Of course, none of this is going to check out if you have a bad ground connectioni between the battery and the engine.
 

oldman570

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Re: 25 Merc electric won"t turn over

If the starter runs normally off the motor but not when installed, then you are either installing it wrong (somehow twisting the housing so it is binding) or there is a wiring issue. If the ground jumper happens to be on a painted bolt, you do not have a good connectioni. It needs to have a resistance free connection to the engine block -- anywhere on the engine block. Since you are connecting jumper cables to the battery clamps and not directly on the battery posts, you need to make sure those battery cable clamps are clean and tight. At the solenoid, remove the cable that runs from the starter to the solenoid. Now connect the positive jumper directly to that cable. If the starter runs, fix/replace the cable. If it doesn't, the starter is being bound up or something is changing with it when being mounted. Of course, none of this is going to check out if you have a bad ground connectioni between the battery and the engine.

Check the starter gear to the flywheel. If it dosen't disengauge and stays in the fly wheel , it will cause the starter to not spin because the starter will not have the speed up to engauge the flywheel an spin it over. This happens quite often when the motor hasn't started. This can also cause the starter to go bad if the gear is stuck and one keeps trying to start the motor for extended time.
Oldman570
 

steelespike

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Re: 25 Merc electric won"t turn over

Not having read all suggestions;have you tried a known good battery like out of your car?
 

goblerblaster

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Re: 25 Merc electric won"t turn over

Thanks, It is hanging up and not dropping down to disengage. I also found that at sometimes, I wam getting voltage on the starter side of the solenoid when the starter button is not pusshed in. Other times I do NOTget voltage on the starter side of the solenoid when the starter button is pushed. I am going to replace the solenoid AGAIN and see what happens. I think I shorted out one of the starters with all this JUMPER cable messing around. The positive lead hooked to the positive bolt on the started sliped off, hit the engine block and the starter positive bolt at the same time. Big arch and now it will not turn over even when off the engine.

I am baout ready to demm this a ROPE start model and take off the starter , and tape up the ends of the wires !!!

By the way, the battery is brand new and fully charged and getting good voltage to everything.
 

oldman570

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Re: 25 Merc electric won"t turn over

Thanks, It is hanging up and not dropping down to disengage. I also found that at sometimes, I wam getting voltage on the starter side of the solenoid when the starter button is not pusshed in. Other times I do NOTget voltage on the starter side of the solenoid when the starter button is pushed. I am going to replace the solenoid AGAIN and see what happens. I think I shorted out one of the starters with all this JUMPER cable messing around. The positive lead hooked to the positive bolt on the started sliped off, hit the engine block and the starter positive bolt at the same time. Big arch and now it will not turn over even when off the engine.

I am baout ready to demm this a ROPE start model and take off the starter , and tape up the ends of the wires !!!

By the way, the battery is brand new and fully charged and getting good voltage to everything.

The feilds, armitureor brushes is bad on that starter now,best to take it to a Good rebuilding shop for repair. Anytime a starter hangs the bendix gear in the flywheel ALWAYS turn it over by hand to release the stuck bendix before trying to start it with the electric starter. Sounds like your problem was orignaly a bad battery and starter bendix, then went from there.
Best to sit down and relax with a cold one before trying again . ThenRemove starter cable from sel. recheck that ALL the wires on the selinoid are on the correct terms. ,very easy to have reversed small terms. on 4 term. sel. and test with a 12V. test light from the block to the starter term. of sel. , test light should not be lit. When switch or starter button is pushed or turned sel. should click and the light should light up. If all checks good then disconect light and check the starter bendix to see if it will move out on the starter shaft and back very easy. Light oil (sewing machine or 3&1) can be used to lube the bendix on shaft, never any grease. Replace the starter cable, and try to start. Should spin motor easy. If not, Have another cold one and start over.
Oldman570
 

goblerblaster

Petty Officer 2nd Class
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Dec 26, 2011
Messages
176
Re: 25 Merc electric won"t turn over

Thankls for all your input- to everyone. I have replaced the Solenoid- this is nuimber 3 - and the starter is working. It still has a tendancy to want to hang in the flywheel sometimes, but at least it will turn the engine over !!!

Again, thanks.
 
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