My outboard caught fire today

[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 unforseeable as the short looked to have occured inside the regulator which is resin sealed fix and move on.

Garry