A bit of a scare this weekend

We had a bit of a scare this weekend and I thought I'd share it in case it happens to anyone else.


We had just pulled into the lock at Ice Harbor Dam on the Snake River and had gotten secured to the bollard. I was on the fly bridge and my wife was on the walkway on the stbd side of the boat.

She yelled up to me that she smelled something very hot. I hot footed (OK, bad pun there, sorry!) it down and could smell it also. I opened the hatch to the engine room and was greeted with a bit of smoke and a strong smell of smoke, and a whirring sound I'd never heard before.

I went down into the engine room and discovered the smell and whirring sound were from the starter motor on the stbd engine. I quickly shut off all battery switches on the main panel (port, stbd and genset/house batts) and the noise from the starter motor stopped.

I left the hatch open so the smoke could dissipate and went back down into the engine room. The starter motor was hot to the touch. Not so hot that I couldn't momentarily touch it, but I would not have wanted to hold my hand there.

I turned the switches for the port and genset/house batts back on and restarted the port engine. After a few minutes I turned on the stbd batt switch and the starter motor started spinning again so I shut it right back off. We were able to make it out of the lock and back to the slip on the port engine.

I went down to the boat this morning and tried the battery switch again and the starter motor spun up again, so I turned the switch back off.

Next stop was my mechanic. I explained what happened to him and turned it over to his capable hands.

I don't know if that could have started an engine room fire or not. It was not THAT hot when I checked it, but who knows what might have happened had we not been stopped inside the lock. Had we been cruising and had the runaway starter motor we probably would not have smelled it and been able to turn it off in time before it self destructed.

Neptune was smiling on us yesterday!

There were a bunch of GM starters used on the Volvo Penta's in the 80's that had aluminum windings. They would melt and start fires when that happened. We had ours rebuilt with copper windings and no more problems.

Could have started with a bad solenoid or bendix on the started(that is if they still have them on the starters). Yes, I think it could very well start a fire. There is a lot of current going through to the starter. Years ago driving older cars we would often have to get under the car to tap the solenoid with a hammer to get it unstuck.

The good news was the failure , probably of the Bendex as it happened.

It could have stuck (instead of releasing) and the starter becomes a DC generator of perhaps 100V , to fry much of the electronics and bulbs.

Then becomes almost a grenade as the fly wheel gets to 1800 and the motoring starter to a zillion RPM.

For those that worry there starters haven't been serviced in decades , a simple re wiring of the Voltage gauge to the starter terminal might show what is happening in time for a shut down.

Its also a great spot to see the actual voltage while cranking .

Seen many starters hang and burn up. Usually they self destruct and failure is contained within. Never seen one start a fire, but it certainly could happen. The bendix has a one way clutch, so as long as that works the engine will not drive the starter to an rpm above what it does electrically. It will draw lots of amps, but not as much as when cranking as motor is spinning at idle.

A good safety hint is after a start, look at your DC volts. If starter has hung, it will be lower than normal. If you see that, shut down engine and go listen.

I went down to the boat yesterday to bring home some stuff from the weekend. While there I turned on the stbd batt switch again and the starter motor spun up again, so I shut if off.


Next stop was the mechanic. (Big Boat Engine Repair & Marine Slips: Pasco, WA: Columbia Marine Center) I explained what happened and he'll take care of it. Seems whenever I get around electricity I recertify myself for my arc welding degree so I try to stay away from high voltages.


We won't be using the boat for about a month so he has time to take care of all the winterization business that he's up to his eyeballs with right now. After he gets caught up he'll fix mine.


I usually try to give him a lot of time to get my issues resolved. That way I know he can give it the time and attention that it needs.

Exactly the same thing happened to us a few years ago. We had just moved 50m or so in our anchorage and the noise and smoke started up. It took a few moments to figure out what was going on and then switched the batteries off. We were only 10 miles from our marina and Coastguard (NZ) came to our rescue and towed us home. The anchor windlass is hydraulic so, without the main engine running, myself and two burly coastguard guys hauled up the anchor and all-chain rode hand-over-hand.
These guys were great and even barged us in to our slip. Very quiet and economical return trip at 7 kn.
I had the starter motor checked out and only a new solenoid was needed.

Great heads up, Mike. I agree with the comment reminding all to verify normal system voltage at the SOC or voltmeter immediately after each start.

In my case, I have one 8D start battery for both engines. If one starter hangs up, I'll see an abnormal voltage deviation on the start battery. I look for that measured voltage rise (back to 14V + or -) after each engine start. It'll show up there long before you smell anything.

I've never really verified the voltage after startup, but I do give a cursory glance at all the gauges to make sure oil pressure is up and voltages are up. I've never really "read" the gauge, just looked to see the needle was up.


I guess that practice will change. Thanks to all of you for the great tips!

Yes, it could start a fire. A N60 had its wing engine starter catch fire because of being mis wired.

N60blossom.blogspot.com

Starter Fire

Several years ago I had to replace the starter on my sailboat (Jeanneau Sun Odyssey 35). I chose a rebuilt. Bad choice. Within the first 10-12 times I started engine, it failed. Turned key to start and nothing. After couple of further attempts, smelled smoke. Wiring harness was on fire. Quickly extinguished with small fire extinguisher and got lucky and got a tow back to our slip by the CG Auxiliary that was operating nearby.

The post mortem showed that one of the brush holders had come loose and jammed against the commutator, preventing motor from rotating. Could have been really bad.

My best friend lost his Westport 52 (and nearly his life) from an engine room fire. Boat burned to waterline and sank. The cause of the fire was never determined, but the event made National News. You can watch the whole rescue at this link: https://www.bing.com/videos/search?...&mid=DD0E04D3E5AC9B12679FDD0E04D3E5AC9B12679F

He was picked up by the orange whale watching boat. I have a recent picture of him at the helm of "TINKA" in my Desolation Sound 2015 Album on this forum.

The video of that boat on fire is what my wife had in her mind when she first smelled smoke. She had visions of our boat burning up inside the lock and it scared the CRAP out of her. She was visibly shaking and shaken when I got the situation under control and could get to her to calm her down. She appeared to be on the verge of going into shock from fear. It took more than a few minutes to get her pulse back down to a more normal range.

We had a similar episode back in Feb this year, the port starter would not fully engage and it continues to source power, luckily we have a fusible link in the ( I think) positive side of the starter cables from the battery , so as the amperage increases it burns the link and stops the power before any damage is done.
I am no marine electrician , but this is what we were told, anyway it worked.

Reduce the risk

GFC said:

The video of that boat on fire is what my wife had in her mind when she first smelled smoke. She had visions of our boat burning up inside the lock and it scared the CRAP out of her. She was visibly shaking and shaken when I got the situation under control and could get to her to calm her down. She appeared to be on the verge of going into shock from fear. It took more than a few minutes to get her pulse back down to a more normal range.

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I read an article some one posted, here I believe, about interconnected smoke detectors. I bought 3 on Amazon for total cost of under $100. Put one in engine room, 1 in pilot house and 1 on flybridge. Even though my engine room is fully clad with sheet aluminum (3/16th holes every inch with film & soundproofing behind it) when alarm goes off in ER, the other two go off as well. The units are battery powered and wireless. This setup would have saved my buddies 52 ft boat. He was alone on boat, on flybridge and didn't hear alarms in pilot house in time. This simple inexpensive system would have most probably given him enough warning to extinguish incipient fire before it got out of control. Here is the link: http://stevedmarineconsulting.com/special-edition-smoke-detectors/

My SeaRay has an alarm system installed that gets its data from about (guessing here) twenty different sources. The wiring to the display board was destroyed when the starter motor fried everything so they are replacing it with a new display panel that will give an LED readout of where the fault signal is coming from.


There was (and will be) a display panel at both helms and both helms will sound alarms if a fault code is received.

So how common is it for a boat's starter to turn on without human intervention and keep running?

Right after we bought our Detroit 8.2 powered Californian 34, I was testing the fuel gauges; turn the key on, run back & wiggle wires( remember, this was sailor travelling up the powerboat learning curve). Smelled smoke & heard a crackling sound. Shut switches off, opened helm panel access hatch & checked for fire; smoke only. Crackling noise turned out to be a loose cover flapping in the breeze. By now, dock neighbors had arrived & filled the salon; bodies & advice. All of a sudden the port engine started. Hard to believe how fast a full boat can go to empty!. Used the manual shut off to kill engine before things really got out of hand. Turned out the buzzer gizmo caught fire, shorting out the ignition switch, as in melted, & triggered all the excitement. Other than that sort of event I haven't heard of many self starting engine issues.

Chris, good thing you were onboard at the time of the failure.

ABYC requires fuse protection on the positive conductor of any battery but for batteries for starting engines. I think they dropped the ball on this one. This is a very good case for fuses on all positive battery conductors.

Yes...but would a fuse big enough to start, blow after the engine starts and the starter just keeps spinning? What is the amperage increase if any ?

Like Ski said...not uncommon...but fires are rare and what amperage do you fuse for?

I have had 3 stuck starter incidents with hot starters but no fires. One took hours to find.

psneeld said:

Yes...but would a fuse big enough to start, blow after the engine starts and the starter just keeps spinning? What is the amperage increase if any ?

Like Ski said...not uncommon...but fires are rare and what amperage do you fuse for?

I have had 3 stuck starter incidents with hot starters but no fires. One took hours to find.

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That spinning starter motor would have eventually seized. Where would the current go then or how about a solenoid locking up until it glows. I have seen the results and now have fuse on all my batteries.

boatpoker said:

That spinning starter motor would have eventually seized. Where would the current go then or how about a solenoid locking up until it glows. I have seen the results and now have fuse on all my batteries.

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True the locked rotor amperage would be way higher...but I think most wiring is bigenough...now you have my curiosity up...yes ...yes... I do have it fused...but I understand the no fuse concept.

Still though...with so few fires despite runaway starters...I wonder why unless the ampacity of the wire is usually close enough.

800 to 1000amps going to a starter is way too much for me. (seize, melt, short, starter or solenoid) I feel safer with a fuse given the stuff that I have investigated. A fuse on all my positive terminals is real cheap protection.

Thanks for the info Sharpseadog, about the wireless smoke detectors. I just ordered 3 for my boat. What a great idea.

Cheers, Bill

Sorry to hear Mike. Good reaction to the situation. It would appear to be a starter solenoid/relay stuck closed. Should be a simple starter w/solenoid replacement.

Man that is a bit of a scare! Good info, thanks for sharing. Glad you were in a Lock and tied up when you discovered it.

We just installed 3 water alarms forward, engine room and stern lazarette. We're thinking about installing smoke alarms and a camera in the engine room as we don't have them. If anyone has any specific suggestions on them feel free to pass along.

Both Kidde and First Alert have wireless battery powered smoke detectors. I put one in engine room, one in pilot house and one in cabinet on flybridge. If engine room unit is tested or activated, both the others also activate. I cannot stress enough the importance of hearing alarm on fly bridge. My best friend lost his Westport 52 (and nearly his life) because he was on fly bridge and couldn't hear alarm in pilot house.

boatpoker said:

ABYC requires fuse protection on the positive conductor of any battery but for batteries for starting engines. I think they dropped the ball on this one. This is a very good case for fuses on all positive battery conductors.

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I think they figured it out before writing the standards. The current draw of the starter is close enough to the capacity of the cable (and the capacity of the battery) that circuit protection that would allow for normal operation would be ineffective.

A starter that continues to run is not going to blow a fuse or trip a circuit breaker. It's going to draw less current running free than it does trying to start the engine.


It will draw the maximum current if it cannot turn at all. As in a locked up engine.

I had a starter do this on a Westerbeke diesel in my ex Navy Whaleboat. Heard the whine after starting, shut down the engine and the whining kept going. Put my hand on the starter and felt the hum. Rapped it lightly with a hammer, and it quit. Never done it again.