My outboard caught fire today

[kwaka]

Hi.

Launched my new (second-hand) boat today, which ended with an engine fire 10min into the test run. It's a 16' runabout with a 1993 Johnson 150hp Fastrike outboard.

Apparently the boat has seen very little use in the last 12 months, and it looked ok when i inspected it.

Before launching it, i ran the motor a couple minutes and noted that the telltail was passing a reasonable amount of water (straight and steady), which looked ok to me. So I decided it was ok to proceed with a run. I did notice that the tachometer was not working however, and put it down to a faulty gauge.

After a quick 3-5 minute run, the engine cut-out on me and smoke billowed out the cowl. I immediately turned the ignition off and used an extinguisher. It smelt like an electrical fire. Got a tow back by the Maritime.

I later checked the motor and noticed that the regulator was severely cooked, and it has spewed plastic over the surrounding harnesses. I noticed that the red wire leading from the regulator to the positive on the motor was totally burnt and cut in half.

Anybody know what could have caused this to happen?

The motor sounding sweet and didn't miss a beat while it was running.

I checked the underside of the regulator and it seemed to have just the usual traces of salt, and not really corroded.

Do regulators depend on water cooling from the underside (fins) and how would you know if there is water flow to it, if the telltale seems to be flowing ok?

I've contacted the seller and will try sort something out, but in the meantime I need some info to go with.

cheers.

[Hamish73]

regulators dont rely on watercooling.
The fact that the red wire is burnt out indicates that an external fault caused the meltdown, possibly a short in the wiring somewhere, as opposed to a fault with the regulator. In other words, replacing the regulator will probably result in a repeat performance, so I'd be doing some tests before going too much further.

[seatime]

maybe a professional opinion? a sparky or outboard mechanic may spot if some backyard amateur electrical wiring has been performed.

or post some photos, someone might spot the fault??

must have given you a fright, good work putting the fire out.
fire blankets are handy in those circumstances, they can be wrapped around the motor, and there's no mess to clean out afterwards.

cheers
Steve

[Burley_Boy]

Sounds like a dead short somewhere, usually caused by a wire shorting to the case somewhere, surprising that there was no fuse that went first, need to check the fusing situation and then trace the short the other side of the regulator, either it cooked all the way through or the regulator is shorting to earth.
good luck.

[kwaka]

I took some photos but need to upload them someplace first to link them (not sure where).

If anybody knows a good mechanic that works the St.George area(NSW) please let me know.

I don't really know what to look for when it comes to electricals. I don't really understand how an external short melts down a regulator?

What i do know however is that I'm glad I took an extinguisher, and there's nothing like an unwanted BBQ to get the adrenaline pumping.

I'll post some pics when I figure out how to.

Cheers.

[Poodroo]

Tachometers not working is normally a good indication of a short somewhere too. Would not surprise me once the wiring fault is found and replaced as well as the regulator and you will also have a working tacho as well.

Poodroo

[Hamish73]

try www.photobucket.com (http://www.photobucket.com) for hosting your pics, then just copy the link into your post

[Roughasguts]

Poodroo, makes sence.
Either a stuffed regulator which it probably is now! or prior to it a stuffed rectifier.
I have no idea what that motor uses.

Have you got a twin battery set up ? and charging both.
That could cause a melt down, trying to pump Max Amps that along with coroded wire terminals.

Have you checked the engine main fuse, thinking that should have blown first.
But maybe not as the battery would take all those big Amps out, anyway see what Amp fuse is in there it may be way to big.

[newchum]

kwaka, mate you say the red wire from the reg was burnt and cut in half. it's possible that where the wire is parted is where it has maybe rubbed through and shorted to the motor case. causeing the reg to hemerage. don't look for a fuse in the red wire there is none. before replaceing the reg get someone to check the the rest of the wireing it may have suffer some heat damage

[kwaka]

Here are the pics:

http://i178.photobucket.com/albums/w260/kwakabaron/IMG_3603.jpg
http://i178.photobucket.com/albums/w260/kwakabaron/IMG_3608.jpg
http://i178.photobucket.com/albums/w260/kwakabaron/IMG_3605.jpg

http://i178.photobucket.com/albums/w260/kwakabaron/IMG_3604.jpg
http://i178.photobucket.com/albums/w260/kwakabaron/IMG_3609.jpg

[FNQCairns]

This is real typical of outboards, the rectifier dies takes the regulator with it then the charge coil under theflywheel keeps pumping the amps result is a fire, guaranteed the tacho was not working, if your tacho stops there is a good chance a call to be towed is in order if you cannot diagnose on the spot or atthe very least a slow trip home to keep the amps down.
Kwacka the coil under the flywheel is shot also I suspect, try in the USA for sierra parts (better than original) and a damn side cheaper with freight of just a week sometimes, suspect in Oz your bill could be $1000 just for the bits that died.

[newchum]

This is real typical of outboards, the rectifier dies takes the regulator with it then the charge coil under theflywheel keeps pumping the amps result is a fire,.
fnq, not sure that what you are saying can happen, as the coils under the flywheel (which has been removed in the pics) generates a.c. current and once the rectifier open circuits there is no d.c. output from the reg and the red wire looks like it has taken a lot of current , looking at the melted bit on the end of the wire coming from the started pos. i think there may be a burn mark on the motor where it made contact. the coils under the flywheel would be melted as well if the fault got its power from them. my guess is the fault burnt the reg out and then got its power from the battery.

[kwaka]

More info:
-I only have one battery.
-I didn't remove any coils, just the top cover and the regulator for the photos. There are ignition coils (large coil pack) mounted on the back of the motor.
-The fuse didn't blow.
From what I can see, the molten plastic from the regulator damaged some of the wiring harness beneath it, and that red wire from the regulator to positive terminal lost all of it's shielding and severed.
Cheers.

[finga]

Have you got a picture looking straight into the battery feed stud on the start solenoid??
I don't think the burnt wire goes to the solenoid terminal in the picture.
Is the solenoid terminal in the picture go to the battery or to the starter??
Newchum could quite well be on the money and it was just a jesus box blowing. Why Jesus box??? 'Cause when that goes you start praying.
Anyways the spewed plastic is just the pichy/resin type stuff out of the regulator/rectifier and not to much to worry about but definitely get the rest of the wiring checked.
A blown rectifier is just one of many reasons why a tacho may not work
Bit of a bad start to Ausfish matey. I hope things only get better and love to hear some good reports from you soon
Cheers Scott:)

[kwaka]

Yes the red wire goes to the starter solenoid post.
I don't think it has a rectifier? Here's a diagram of my motor >> http://www.crowleymarine.com/brp_parts/diagrams/38636.cfm

Thanks for all the responses and yeah, i do hope things work out and I get more than a couple minutes of joy from my investment.

Cheers.

[FNQCairns]

Kwacka you will need to pop the flywheel (or at least remove the cover to take a peak) and check the coil it should be melted and dripping even, it's all very typical of outboard fires, they run so cool there is simply not much else apart from a really good overheat or a general short in high amp wire like starter/battery cables.

I have always assumed it was the coil still pumping to short that causes the fire, I really do not know if it could be the battery feeding back like you say Rodney, in all the times I have seen it I didn't think of the battery.

Still if ever the tacho stops consider it an important episode (if only to save your pocket of the hundres the charge coil can cost) if a person is not able to diagnose whether charge is still being supplied at this point the best option is then a tow.

cheers fnq

[blaze]

46 439561 rect/rgltr&gskt Ay

[Roughasguts]

What motor is that Kwaka, Some Mercs have there wiring harness bundled to tight, and that ends up cutting the insulation.
And if that opens a positive and a Negative, well away she goes melting all the shielding on the wires and genarally making a mess.
So not un common with some Merc motors, trying to think which ones 135Hp maybe.

Did you un do any bundles of wires, after the melt down ? would have been zip tied up pretty tight.

Then again the zip ties are probably melted away.

[kwaka]

It's a 1993 Johnson 150 Fastrike. I removed the burned sheilding to check the wiring damage, and found most to be relatively ok. Only a handfull of wires melted together (and the red one that fried). I'm hoping that all that will be needed is a new regulator, some minor wiring repairs, and a bit of time for a mechanic to check it all out.

FNQ, when you say i should check the coild beneath the flywheel, are you refering to the charging stator?

[FNQCairns]

yes there is a good chance of it being on your shopping list, were you running without your tacho? if it was still working in the very few minutes before the fire started your stator could still be OK hopefully, but I expect the worst, very happy to be wrong they cost a bit.

cheers fnq

[Roughasguts]

Sorry Kwaka, that info was in the first post about what motor.
Find out what you need and ring around a few outboard wreckers that might keep the price down a few hundred dollars.

But as said before Siera, in Canada I think should have most of your parts after market.

I feel for you mate, the boats going to be a bit hard to trust for you now.

[kwaka]

The tacho wasn't working at all during the run.

[finga]

Usually when the rectifier/regulator go bezerk they open circuit. This one looked like it short circuited and hence the huge current and molten wire.
If the insulation wires going to the coils is not blistered you should be right but best to be on the safe side though and get it checked.
PS that's an excellent site for reference. Ta muchly :)

[Noelm]

yep, a fire on a boat is sure something you will remember, at least it went out fairly quick, I had a real "doozey" of a fire once ,on an old 'tower of power" merc, sh!t what a feeling! it was kind of funny now, looking back at the ordeal some twenty years later! I might as well tell you about now huh!, we had an old 115 in line 6 merc, that had a carby flooding problem, we had tried heaps of times to fix the problem, but like MOST people, tried to do it cheap and not buy any parts, it would be OK if you gave it a 'whack" on the carb ,so we had a 12" roller pin in the motor well for just such occasions, one day we started it up and it was flooding like hell, petrol dripping into the motor well, so off with the miracle of engineering that was a Merc cowl, grab the roller pin, hit the side of the carby (motor still running mind you) and my mate must have touched the starter terminal or something, because as he hit the carby there was a blinding flash and that unmistaken "WHOOOMPH" that copius amounts of petrol make when ignited, of course it spread to the motor well too, SH!T grab the extinguisher, only trouble was the bracket had rusted off, and it was held in place by some 200LB breaking strain fishing line, tried like hell to break it, but no way, and the only knife was in the tackle box, which was now on fire too, we were about to jump off, when by miracle it just went out, the motor coughed and spluttered but kept running for a while, moral to the story, do not be a tight arse on repairs, make sure your safety gear is usuable and accessable, but al least it is a good story now!

[Burley_Boy]

I have too much respect for FNQ to second guess his remarks but at the same time I have had a close call with a battery short to case (wiring melted deep into the fuel line...) hence my reference to check the fusing situation from the battery.
There are two points I believe that will generate the high current and one is from the coils under the flywheel and the other is from the battery. The battery will generate way more current but is usually protected by a main fuse before it becomes 1mm cable or the like. In my case this fuse had been bypassed thus extreme current capability in the wiring.

My thoughts are about that picture that showed the burnt wires on one side of the connector but no damage out the other side. Just looks to me like a short in the connector or between a wire and the case at that point. I would have expected the burnt wiring to extend through the connector otherwise.
On the other hand I am in no way an expert on your model engine.

[kwaka]

Update:
The regulator was replaced today by a mechanic and the engine appears to be running fine and charging at 14V+. The battery holds charge and I'm pretty sure the tachometer works normally now. I'll test it on the water in a few days to confirm all is ok.

Cheers.

[finga]

Beauty, excellent :)

[FNQCairns]

Back on the water thats good news, what was the final cost? If that is not a rude Q. You have got away with it well in my experience.

These things can be unavoidable I have had it happen to a Mercury twice (same engine) during warrenty, an OMC and an oldie OMC down stairs also has the disease, also 3 other times on other peoples boats. It's a bugger when there is nothing solid that can be done to improve the risk so I keep a sharp eye out now for the telltail signs - probably will never happen again.

cheers fnq

[kwaka]

I received quotes ranging from $550-$700 for new regulator fitted and tested.
Yeah, it will be great to get out on the water after a false start.
Cheers.

[Spaniard_King]

Just a dead short in the regulator/rectifier... big bucks tho :P unforseeable as the short looked to have occured inside the regulator which is resin sealed fix and move on.

Garry