Help! Burnt wire!

[Bingobongo]

Hi everyone. New to boating and this forum. This happened to me today while out on the water. I have a 2004 225hp 4 stroke. Located front lower part of the leg. The wire burnt a hole through the plastic while in the water. Can someone tell me what this wire is or does? Thanks in advance!

[rodbolt17]

it is a bonding wire.
it tried to get used as a ground wire.
fix your loose/corroded grounds.

[Bingobongo]

Thanks for the reply. Once the wire is fixed can that plastic covering that has the hole be fixed or patched? Or would I have to replace that whole cover? Sorry I don't know anything about out boards, that was my maiden voyage. What would that specific part be called? Cheers

[Bingobongo]

Is this an easy fix? Could this have done any major damage to the motor? Bought this boat a week ago.....cheers mate

[pstephens46]

Is this an easy fix? Could this have done any major damage to the motor? Bought this boat a week ago.....cheers mate

Will you fix it or will it go to shop? It doesn’t need to be operated until the faulty ground is repaired. More than likely, the motor is fine. Did it shut down while you were running it? Or you noticed the damage later? The cover would have to be replaced, not repaired. Plastic....I wouldn’t bother. Cosmetic. I would probably replace the wire. It protects the lower unit.

[99yam40]

Does the OP know what a bonding wire is for?

It connects the parts of the motor together so what the sacrificial anodes can protect those parts fro corrosion.

Those small wires should not have current from battery or motor charging system flowing thru them.
If it does the wire heats up and melts the stuff around them.

Take it to someone that knows what they are doing if you know nothing about the electrical systems

[Bingobongo]

pstephens46 I'm taking it to a shop to get fixed today. It started/ran fine all day while I was out but when I wanted to head back I tried to start and it wouldn't crank over. Got towed back for 5hrs. Noticed the damage when I was washing the boat.

[Bingobongo]

99yam40 thank you for explaining what that wire does. After a bit of research your explanation was spot on. I'm not risking doing any work myself, taking it to a shop to let professionals fix it.

[zenoahphobic]

Does the OP know what a bonding wire is for?

It connects the parts of the motor together so what the sacrificial anodes can protect those parts fro corrosion.

Those small wires should not have current from battery or motor charging system flowing thru them.
If it does the wire heats up and melts the stuff around them.

Take it to someone that knows what they are doing if you know nothing about the electrical systems

Spot on. It would be obvious that the wire carried way too much current, loose connection would have reduced the current and if this would have been the case the heat from the resistive joint would not have travel up that wire that far (particularly near the water).

It would seem you have a serious "short", and I would not rule out that a battery has been connected back to front in someway. Check whether the starter positive wire has come loose and touched somewhere it shouldn't. The solenoid or carbon brushes or carbon build up within the starter motor could be the culprit.
Depending on your wiring and earth or negative connections an auxiliary or dual battery could also be the culprit by providing positive to the water via some metal and it then travelled to the leg of your engine then up that burnt wire to the bulk of your " earthed ? " engine.

Sorry a bit convoluted, but a strange fault to have.

[FabricGATOR]

You don't see that every day.... at least I don't.

[Bingobongo]

Spot on. It would be obvious that the wire carried way too much current, loose connection would have reduced the current and if this would have been the case the heat from the resistive joint would not have travel up that wire that far (particularly near the water).

It would seem you have a serious "short", and I would not rule out that a battery has been connected back to front in someway. Check whether the starter positive wire has come loose and touched somewhere it shouldn't. The solenoid or carbon brushes or carbon build up within the starter motor could be the culprit.
Depending on your wiring and earth or negative connections an auxiliary or dual battery could also be the culprit by providing positive to the water via some metal and it then travelled to the leg of your engine then up that burnt wire to the bulk of your " earthed ? " engine.

Sorry a bit convoluted, but a strange fault to have.

Thanks for you reply mate. It's currently at the Boat Shop getting fixed. Hopefully all issues are resolved.

[Bingobongo]

You don't see that every day.... at least I don't.

Hopefully I never have to see that again!

[zenoahphobic]

Thanks for you reply mate. It's currently at the Boat Shop getting fixed. Hopefully all issues are resolved.

Please keep us informed what the problem was when it gets fixed. This is a strange one because the provision of those earthing wires seem just as a precaution as there will be metal connections between the lower unit and engine itself e.g. though the drive shaft. Sometimes the metal cowlings are electrically isolated via the rubber mountings and the need to tie them to earth is to galvanically protect them from corrrosion.

[Bingobongo]

The boat shop came to the conclusion that the motor didn't start because the high pressure fuel pump was faulty.

The earthing issue was something seperate. They checked all terminals and connections, replaced the high pressure fuel pump and the motor runs fine.

I have noticed they didn't replace that bonding wire, why I do not know 🤯🤬 it is quite corroded.

I live 3 hrs away from the boat shop so taking it back is a mission, could I replace that sacrificial wire myself?

Is it a special type of wire?

[zenoahphobic]

The boat shop came to the conclusion that the motor didn't start because the high pressure fuel pump was faulty.

The earthing issue was something seperate. They checked all terminals and connections, replaced the high pressure fuel pump and the motor runs fine.

I have noticed they didn't replace that bonding wire, why I do not know 🤯🤬 it is quite corroded.

I live 3 hrs away from the boat shop so taking it back is a mission, could I replace that sacrificial wire myself?

Is it a special type of wire?

I thought this was about a burnt wire. Can't understand you didn't check on it before picking it up and traveling 3 hours 😳

I think the wire is stainless steel, to stop It corroding normally but not from passing a large current through it. It should be replaced but will it burn again?