Help! Burnt wire!

[99yam40]

now if the hull of the boat was metal and they hooked the negative of the house battery to the hull for a return path for lights and other boat stuff, and all of the batteries negatives are common it could happen.

a bad connection for ground from starter battery to the motor, could flow current thru the bracket and mounting bolts possibly

[boscoe99]

http://www.yamahaoutboardparts.com/f...fire-need-help

[FabricGATOR]

this particular wire connects the swivel bracket to the lower casing
so that it is electrically continuous with the powerhead

there is another wire at the top of the swivel bracket that connects to the port side bracket
and another from the bottom of the port side bracket to the t/t unit

(the latter seems superfluous,
given the intimate mechanical connection between the t/t unit and the brackets)

I can't imagine a circumstance where battery power would "return to ground"
through that bonding wire -
other than an internal short to the housing of the t/t motor.

And even that seems implausible.

Hmm, So it appears that this ground bonding is between the bracket grease zerk and the middle casing. The powerhead, midsection, and lower is all floating on isolation dampners. I believe that even the steering tiller is vibration isolated, so it is feasible that little to no engine to hull continuity may exist without that bonding wire. Asides from the engine battery harness ground that is.

So, OP said everything was great until they decided to head towards the beach. It wouldn't start. Likely the captain tried more that once until the battery was exhausted and if poor engine starter grounding were a reality, I now understand how a substantial amount of current could make the bonding wire glow...

I recently removed my Showa Trim Tilt unit and it was all floating on nylon bushings, So again, I can see where without that bonding wire, the T/T unit could also be isolated. Potential for pump operation is green to blue or blue to green, not either / or to ground on that TT unit.

I understand (I think) I can sleep better now...

[FabricGATOR]

http://www.yamahaoutboardparts.com/f...fire-need-help

Well, that was a waste of a good fire extinguisher...

[zenoahphobic]

[QUOTE=rodbolt17;n215638]the amount of misinformation is growing.
that wire is not brittle and will not break.
the plastic covering is simply cosmetic.
you have a ground wire issue.
you DO NOT have a short.
the batteries were NOT hooked up backwards,you did not blow the 60 amp fuse.
it is simply a bonding wire.
holds isolated parts at the same electrical potential.
that is all it does.
[/UOTE]
Not misinformation just guesses, as no one seemed to have seen this before. So how do you explain this? How much current you think has passed through this wire?
You can't just discount everything without offering what you think may have gone wrong other than previously offering bad connections.

[99yam40]

bad connections on the negative side is always the problem with burning those little bonding wires.
nothing else will cause the 12 volt system to seek another return path back to the battery

[boscoe99]

[QUOTE=zenoahphobic;n215667]

the amount of misinformation is growing.
that wire is not brittle and will not break.
the plastic covering is simply cosmetic.
you have a ground wire issue.
you DO NOT have a short.
the batteries were NOT hooked up backwards,you did not blow the 60 amp fuse.
it is simply a bonding wire.
holds isolated parts at the same electrical potential.
that is all it does.
[/UOTE]
Not misinformation just guesses, as no one seemed to have seen this before. So how do you explain this? How much current you think has passed through this wire?
You can't just discount everything without offering what you think may have gone wrong other than previously offering bad connections.

Within Yamaha USA it is a well known issue. I could have sworn that Yamaha USA put out a document about this problem. Damn if I can find a copy.

[zenoahphobic]

[QUOTE=boscoe99;n215682]

Within Yamaha USA it is a well known issue. I could have sworn that Yamaha USA put out a document about this problem. Damn if I can find a copy.

Love the sarcasm. I think it was a world wide urgent fire safety recall notice, Yamaha replaced all the bonding wires with 16 mm squared starter motor cable.

[boscoe99]

[QUOTE=zenoahphobic;n215687]

Love the sarcasm. I think it was a world wide urgent fire safety recall notice, Yamaha replaced all the bonding wires with 16 mm squared starter motor cable.

No sarcasm intended. Just a comment to your comments that it has not been seen or heard of before.

There are a number of issues with respect to any brand of outboard motor that you, I or others (even within Yamaha) may have never heard about. Just the way that it goes.

Yamaha issues technical bulletins and technical articles to alert dealer personnel about a number of issues that might come across their tool box. I am thinking there was one about bonding wires burning up. Trying to find it. Maybe rodnut can help me to remember.

[zenoahphobic]

[QUOTE=boscoe99;n215696]

No sarcasm intended. Just a comment to your comments that it has not been seen or heard of before.

There are a number of issues with respect to any brand of outboard motor that you, I or others (even within Yamaha) may have never heard about. Just the way that it goes.

Yamaha issues technical bulletins and technical articles to alert dealer personnel about a number of issues that might come across their tool box. I am thinking there was one about bonding wires burning up. Trying to find it. Maybe rodnut can help me to remember.

Sorry humour doesn't travel very well between hemispheres. So after 39 posts you are telling us this a known fault......so it is imperative we find out what Yamaha says and what their fix is. I think some of us are not accepting dirt ground connections without some other "fault" causing 12v positive to get to touch something that it should not.

[boscoe99]

[QUOTE=zenoahphobic;n215698]

Sorry humour doesn't travel very well between hemispheres. So after 39 posts you are telling us this a known fault......so it is imperative we find out what Yamaha says and what their fix is. I think some of us are not accepting dirt ground connections without some other "fault" causing 12v positive to get to touch something that it should not.

Mr. Rodbolt addressed this in post #2.

[boscoe99]

https://www.thehulltruth.com/boating...=#post11403054

Seahorse (an Evinrude employee or Evinrude dealer mechanic) is one of the most knowledgeable folks around. I will ping him and see if I can get the theory behind what is going on. I can't remember squat these days.

[boscoe99]

[fairdeal]

tinypic image ]

I can see, and read, that - but I'm not 'getting' it.

If the problem is a bad connection of the battery - to the engine block -

how does current flowing into the t/t unit/swivel bracket/brackets,

make its way to the battery negative terminal?

Unless - and it hasn't been suggested, nor AFAIK is it "generally done" -
a bracket mounting bolt is "bonded" inside of the transom,
to a common electrcial ground.

[zenoahphobic]

So clearly with Evinrudes explanation, this burning of small gauge wires may happen when there is ANOTHER fault condition, not from loose earths alone!