What would cause my starter...results are in!

David Robinson

David Robinson

Well-known member
Guys,

I'm out of ideas so I'm appealing to the "think tank." My 1991 Johnson 25 hp outboard motor will not crank for more than 2 seconds before the starter motor stops. I replaced the starter motor last year and just replaced the solenoid last night and still no change in performance. I've also tried a new battery and checked ever electrical connection for corrosion. If you've got any ideas or a hypothesis, I'm listening.

Thanks,

Dave
 
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A bad spot on the armetur?

You said you checked for corrison, what about electric as various points through the circuit? After the motor stops is there is power there?

Good luck, I am not a mechinic but can usually keep my stuff running.
 
Not an answer but a diagnoses question. Have you tried turning it over with the plugs out? How well charged is the battery?

Kyle Ritter
 
Andrew, I'm not sure what the armature does for the starting circuit, I'll check my book.

Drew, the engine runs like a top, it's the starter motor that won't run for more than 2 seconds. Your question about whether or not there is current being drawn after the motor stops is a good one - I'll try to test that out.

Thanks,

Dave
 
The test with the plugs out is to see if the motor will turn it over without the load of the engine compression.
Did you get OEM parts for the repair or remanufactured?
 
Bob, I think the starter motor was made in Mexico by ARCO. I bought it from MarineEngines.com. Good prices but it's definitately not OEM. The solenoid was from a local Johnson marine dealer - probably OEM. Why? I'm really hoping it's not the 1 year old motor that went bad :^0
 
We have had mixed results with ARCO. But they do back their stuff. We just cant afford the time for a call back on a bad replacement.
I would be very careful of the battery switch too if you have one. Cable length and any issue with less than perfect connections will hurt the starter over time. Its the hardest job the system does. Upwards of 200 or more amps.
You did not say if the bendix is engaging the flywheel. The plugs removed will tell if it turns the motor with less load or not. easier than pulling the starter and bench testing.
 
Dave you have had some good advice, especially what Bob said. I always try to go with factory parts on boat engines and automobiles as I have had bad luck with cheapo parts in the past on cars and boat motors.

The 25 hp Johnson is in my opinion a very good motor. I once had a 1976 model that I ran for 10 years and still sold it for a profit.

Good luck on the repair,
Harry
 
Bob, good advise! I pulled out the spark plugs and the starter motor cranks forever - just like new:) But what does that mean? I can only guess: may be a bad starter cable or a poor connection in the engine or...weak starter? Any feedback on this test result would be great.

One correction, the starter motor was made by Sierra (not Arco).

You've just got to love the scientific method (that's the science teacher in me, sorry;)

Thanks again,

Dave
 
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Im not nuts about Sierra product after loosing a 25 merc power head in the ice to a sierra impeller I used thinking it was as good as an OEM merc one. The brass bushing Sierra used spun at the first sign of Ice and I lost the top end to over heat. A long other story.

Now I would say you need a good digital volt meter and if you can borrow a DC amp meter you will have it even better.
You still havent verified that the gear is engaging the flywheel? Is the electric starter turning the engines power head when you are cranking?

If so you need to find out why it wont do it with some compression.

Can you take pictures of the electrical connections in the Battery cables?

They should all be clean and shiny with good crimps on the lugs.
How long are the battery wires to the motor....all the way down the Positive and back up the Ground?
Is there a Battery Switch involved? Any connection between the + on the battery all the way to the motor and back to the - should be checked..
Because its easy and this could be causing low voltage or amperage at the starter.
When you next test it you should get a little help. Test DC voltage at the battery to ground when cranking, then at the starter + to battery ground (Not just ground at the engine) when cranking. These all with the plugs out.
Now if everything is working put the plugs back in an get the same numbers.
Then you have some info for the tech at Sierra when you call them to get their help. Battery should be over 12.5 to start and should not go under 10.9 during cranking at any location in this testing.

If the boat and battery are true and not an issue I think the original idea of a bad wire in the winding is a good guess, but you also have a new solonoid from someone else and that means another company to talk to.

25 hp does not take a lot of amps to turn over so I am hopping you have an easy to fix wire end but you may need a warranty on the motor.

As I said above I dont service outboards for a living but I do fix my own and starting circuts are the same for gas or diesel from 5 hp to 1500hp, just bigger cables.
 
Bob,

Thank you so much for your time and help with trouble-shooting this motor. I just bought a DVOM and tested the battery wires for any resistance and found none. I also checked the lead + wires in the starter circuit and cleaned all the electrical grounds and wire connections (again:). I'm going to have to read up on voltage-drop tests and amperage tests. I get what your testing, I just don't want to fry myself or the DVOM.

The bendix gear does jump up and engages the fly-wheel and will turn the engine (with plugs installed) for 2 seconds. Without plugs, the starter turns like it should and cranks the engine.

Since our last conversation, I brought my boat into the dealership so he can test the starter to see if it's weak. I'll let you know results later tonight.

FYI: my boat dealer is not crazy about Sierra replacement parts either. He said its a crap-shoot on quality since the parts are made overseas.

Thanks,

Dave
 
Buy Nigel Calders book on electrical repairs.
I think it is called boatowners guide to electrical repairs.
Get the 3rd edition as it is the most current.
It is not cheap but is avail. on amazon and the chapter on voltage testing with a DVM alone is worth the price. It goes into detail about how alternators work and starter motors. Also fuse protection and wire size.
Way more than you need for a duck boat but you can sell it after you read it.

I think you are on your way. I hope your mechanic can test your battery as well as the starter.
 
Well, at least the electrical wiring is good, LOL. My mechanic has determined the starter motor's gear drive is sub-par. It was so poorly manufactured that it was not letting the motor get it's job done. So $30 in parts and $100 in labor, a new OEM gear drive was installed and should solve the problem. I'll find out Tuesday when I pick it up. At least I'll have it for my U.P. vacation that starts Tuesday! Look out fish:)

Also, a big THANK YOU to Bob and the others that have helped me through this crazy starter problem. I love this site and really appreciate the help and the vast amount of knowledge that's freely shared between waterfowlers.

Thanks,

Dave
 
I've been fighting all kinds of ignition issues in my '93 Merc 40. In the defense of the motor I had a battery strap break and the battery shorted out on the boat but that was 2 years ago. I tried everything that I could do, replaced the switch box, checked the coils, wires etc. Finally, I took it in and now that the trigger has been replaced he's telling me that my stator is bad and two coils are not right either. Basically the entire ignition is fried. So, a quick lesson....ALWAYS keep the battery in a battery box with a lid!!!!! Just thought I'd share that the pain can get much, much worse when it comes to outboards.
 
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