Outboard won’t start I only get a single click

[ATPNW]

Was out on the water earlier today trilling. All of a sudden one of my motors (2005 Honda BF50) made an abnormal sound. At the time, I knew it was a familiar sound as it was almost like a higher pitch revving up of something. Within a second it stopped, both my dad and I perplexed couldn’t figure out what just happened. But now everything sounded fine. We fished for another hour trolling. Then headed to the dock with no issue. After tying to the dock, turning off the motor, then getting the trailer I tried to motor up to the trailer. I tried to start that motor but it wouldn’t start. Only a single click. Thinking about it now, the weird sound earlier I’m pretty sure was the starter engaging. My dad said he didn’t touch the key to engage the starter. Things I have tried:

1) kill switch
2) fuel line
3) battery on and charged
4) bench tested starter
5) bench tested solenoid

I still only get a single click. The two things I can think of next are a loose/dirty connection. Or a seized motor, although I really don’t think it’s this of it was running perfectly fine just before. Anything else you all can think of?

I will add that I took off the cowling and when trying to turn the ignition I can see the starter motor spring up and engage the gear, but won’t turn the engine over. I have tried a few times and now the starter motor is stuck in the upright position

[ATPNW]

Update: looks like the motor might be seized. Pulled the spark plugs and tried to turn the flywheel and couldn’t do it. Could not find evidence of water on the plugs nor the cylinder head when I bore scoped them though. This whole ordeal is so bizarre to me. Have no idea where to turn next or what to do.

[srbaum]

Atpnw,
Most outboards that have a failure as you have experienced, have catastrophic damage inside of the engine. Usually overhaul of an older powerhead that has internal damage is not cost effective.

[T.R. Bauer]

That's terrible to hear it's locked up. And given the circumstances, incredibly odd as you noted. I happen to agree since it was just running. Are you certain it is locked up? It's just crazy. If it is truly locked up, man I'm really sorry

[ssobol]

Did you check the oil?

Once my engine would not start. It was running fine, but the next time I tried to start it, I got a single click of the starter. It was a bad starter.

[T.R. Bauer]

[thataway]

Have you borescoped the cylinders? What does the oil look like? I probably would drain it and look for metal shavings. Maybe even do an oil analysis.

What you describe still makes me thing that there are issues with the starter/system. Was the Bendix gear free of the flywheel when you tried to turn it. Did you use a breaker bar with a socket on the flywheel nut to see if you could rock the flywheel over with more leverage?

To be complete load test the battery (cheap Harbor Freight 12V load tester is adequate for this)

Also just because the starter runs on the bench does not mean it has the power to turn the flywheel. Often it is corrosion on the various terminals for the heavy cable from the battery. Perhaps most neglected, is the ground to the frame of the engine. But it sounds as this is eliminated if the flywheel will not turn by hand. We used to start the 40 and 50 hp outboards with the rope on the flywheel.

Hard to understand why it ran perfectly, no known overheat, no sound of seizing up. Then seemed to seize up and not restart.

[ATPNW]

I did disengage the bendix from the flywheel, still wouldn’t turn. I inspected the oil fill cap and dipstick but didn’t see any milky residue… The last oil analysis less than 10 hours ago didn’t turn up anything unusual. I’ll try and post pictures of the spark plugs and bore scope pics later today. I’ll remove the lower unit and try the breaker bar. When doing that, I’m assuming I’m going to grab onto the 4 bolts on top of the fly wheel? Maybe with a large crescent wrench?

Thanks for the help and suggestions so far. Had to head east for the day (family emergency). So other than the pictures I’ll post later I probably won’t get much time working on it. But I’ll be sure to keep updating.

Edit: or is this what I’d use to try and turn the flywheel?
https://www.amazon.com/OEMTOOLS-25556-Flexplate-Flywheels-Specialty/dp/B0949M63L8

[thataway]

I would go with the strap wrench you linked to. See if it will rock a little. If not then it sounds like tear down vs new engine time....If you can do the rebuild, then not too bad, depending on what damage there is to the block and crank shaft/bearings etc. There is going to be a point of diminishing returns... Unfortunately a seized 50 hp Outbotd motor has little scrap value...

[C-Wolfe]

I have one more thing to add from everything mentioned above before you start opening up the engine. I got a similar thing happen to my 2006 BF50 on a multi day trip, I was very lucky that it solve itself until I could figure out what had happen. One of the magnet came loose from under the flywheel and wedge itself enough to kill the engine, but apparently barely as the engine started right back up and made it home ok. You might want to remove the flywheel before you put too much tork on it just in case. Hope this help

[Robert H. Wilkinson]

I had a 10hp honda generator once that was working fine when I stopped it then next time it would not turn over. It would stop turning abruptly and you could back it up almost 1 rev then it would stop again. I thought for sure the connecting rod had come off and was jamming it. When a Honda tech told me it could just be carbon I thought he was nuts. He took the head off scraped the carbon off the piston - cleaned it up and put it back together - even reused the head gasket. Worked fine for hundreds of hours after.

I don't think this is your problem - just sharing my experience.

Rob

[ATPNW]

Thank you all! It would appear C-Wolfe hit the nail on the head! One of the magnets came loose on the flywheel, and got lodged up there. I reinstalled the flywheel minus the broken magnet (for testing purposes only) and was able to hand rotate the engine, phew! While I have you here- I have also posted a picture of my spark plugs from this engine, cylinders 1 and 3 appear to be carbon fouled. I troll a lot, so carbon fouling might be expected? But wouldnt I also expect to see cylinder 2 carbon fouled? Would this point to the valves needing adjusting? Thanks again for everyone's help

[C-Wolfe]

There's mine.

[thataway]

Good call on the magnet! Probably one of the cheapest things which could be happening to cause your problem. Did the flywheel turn in the opposite direction?

The spark plug fouling: may be too rich mixture from the carburetor. You might try adjusting that. Are all spark plugs the same? Too cold a plug for that prolonged idling could be an issue.i. Certainly the plugs need to be switched out, and of course the gaps reset. How is the rest of the ignition system?

[ATPNW]