F60 4 Stroke start probs SMOKE!!

[giffo]

I have a 2004/5 Yamaha F60 High Thrust 4 stroke. Runs beautiful.
I have twin batteries (1x start, 1x accessories). I always run it at least once a week for 20 mins or so when not using.
I started it a few days ago and ran like a charm.
Went to start it yesterday and I turned the key. It tried to start. A few clicks of the starter then i saw SMOKE coming from the lower leg area. I smelt electrical smoke. I checked my batteries and all look good (wiring).
I used the pull cord (manual start) ignition on, started no problems.
I took some plastic covers off on the front of the leg and tried to start again.

SMOKE.............. Then i saw where the smoke was coming from. It was coming from the stainless steel wires that run from the top steering arm to the leg (where grease nipple is and to the leg)......
Anyone know what this could be? Obviously a short somewhere. But why on the earth (if earth) wire??? Is these wires an earth or something else?
I notice the stainless wire had was covered until now... (insulated). broken off and heat caused it to fall apart...

Any ideas fellas??

Steve- Australia (Sydney)

[captain rednut]

smoken earth

hi i have seen this several times before and reverse polarity was the cause in those motors, so check the battery cableing and disconnect the main dash power feed and try again as it maybe an apliance causing it???
i hope it helps? good luck jim

[giffo]

Thanks Jim will do. The thing is everything has been good till now. The boat was okay one day and without touching anything. Then 'Boof' this happens.
Bit sus!!

Cheers

steve

[giffo]

Hey Jim,

Checked all my cables. Changed batteries (from accessory battery to start battery)position 1. Still wouldn't start.
So i put the start battery on acc. side of switch. (Position 2) IT STARTED!!
So I knew it was not my batteries.
I checked the twin battery switch. All good.
Then i thought for a minute............"EARTH LEAD" Mmmmm
Re-applied earth lead on boat (aluminum)
GUESS WHAT???? IT STARTED. BOTH BATTERIES. Well I'll be damned.!!
Was the earth lead all along. Filed back the alum (from paint) and presto!

So I thought about it and now the smoking at the earth lead on the leg makes sense. Bad earth, so it had to go some where, hence leg.

All fixed and running good now. Off fishing I go tomorrow.

Thanks mate.

Steve

hi i have seen this several times before and reverse polarity was the cause in those motors, so check the battery cableing and disconnect the main dash power feed and try again as it maybe an apliance causing it???
i hope it helps? good luck jim

[mitch]

What are you saying ? that the earth lead is attached to the hull or the motor .


if it is on the boat hull you are going to have big electrosis problems your boat will be eaten .

[giffo]

What are you saying ? that the earth lead is attached to the hull or the motor .


if it is on the boat hull you are going to have big electrosis problems your boat will be eaten .

Mitch,

The main earth lead is attached to a special welded plate on the transom (alum). There is a stainless steel wire on the leg and trim and tilt bracket.
All (most) aluminum boats have the same thing as far as I know..
There is the usual electrolysis cancer, but only small stuff around cleats etc.
My boat is 5 years old and still in good cond.

Cheers

[99yam40]

normally the negative battery lead is bolted to the motor at the starter to keep the starting current from running through anything else including any of the stainless wires that are there for electrolysis corrosion prevention

[mitch]

where are your other earths ? for lights and other equip running back to battery or hull ?

like 99 said it should be on your motor not hull that,s bad .

I take it you use your boat in fresh water .

[giffo]

Bloody hell, I get your message fellas. My boat was built like that too! Will definitely find out and get it moved.
Many thanks all.
Worried!! (Steve)

[mitch]

no believe he is saying the battery earth is attached to the transom ? other wise why would a bonding wire burn

[99yam40]

I am not quite sure how the starting current would flow with the starter battery negative tied to the hull.
The motor is riding on bushings in the pivot points, unless there was a bonding cable installed from the boat hull and the motor block or starter itself, how could the current flow through the rubber mounts and plastic bushings?