T8 rusting problem

[chadmyrvik]

I have a 2003 t8 that I have been fighting a rusting issue. All the nuts and bolts under the water line are rusting excessively. I used it for two hours last night, it had new hardware installed, and it was completely covered in rust this morning. Any ideas of what I should be looking for? Thanks for any info you can give.

[TownsendsFJR1300]

Are you using stainless steel hardware and are all your anodes in good shape?

[chadmyrvik]

I used the Yamaha hardware which I don't think is stainless steel, they feel more like aluminum. The anode by the prop was new this year and in good condition, the one by the mounting bracket isn't new but it hasn't deteriorated at all. The ground wires that attach on the grease zerk are also falling apart due to rust and they were new this year as well.

[fairdeal]

there's something interesting - and very wrong -

going on here with "stray electricity" that is driving abnormal corrosion of those stainless and bronze parts.

is this in freshwater or sea?
Is this a "kicker" on a larger boat?

larger engine / generator on board?
docked with shore power?
docked with neighboring boats?

[pstephens46]

Ground wire on lower unit is definitely good stainless. I have never seen any rust around mine. How do you test for stray electricity?

[fairdeal]

more information that most would want:

Types of Marine Corrosion - BoatTECH - BoatUS

[chadmyrvik]

It is in fresh water, it is a kicker motor. I also have a 200 vmax that hasn't had any issues with it. I did have it plugged in to shore power over night but the kicker motor was out of the water. There were other boats around but it seems to happen no matter which slip I am in. It only seems to happen after the motor has been used. I added a new minnkota battery charger a couple years ago and it seems to have all started a short time after that, is it possible the battery charger or a bad battery would cause anything like this?

[fairdeal]

generally, "rule #1' for boats is to have all metal objects, especially all wetted metal at the same electrical "potential" - accomplished by "grounding" aka "bonding' them together.

For instance if you have two motors, each with their own battery, you connect the negatives of the two batteries together. They are not "sharing" the batteries - but that puts them both at the same ground potential.

what batteries do you have on the boat? what is the minnkota charging?

[chadmyrvik]

I have separate starting batteries for each motor and I know that they are not connected in anyway. They never have been connected to my knowledge and I owned the boat for at least 3 years before any of this started. Three Walmart Everstart batteries total in the boat charged by a three bank charger.

[chadmyrvik]

And I greatly appreciate all the help that has been given. I know its a pain in the arse to try diagnose things like this and even more so doing it online.

[DennisG01]

Just echoing what Fairdeal mentioned above, is the *****ing motor battery tied into the kicker in any way, shape or form? Are there any accessory leads coming off either the kicker or *****ing motor. It's strange that this all happened after you installed the tolling motor - that would be the first place I would start looking.

But, if the ONLY way that the kicker battery is tied into either your main motor, *****ing motor, or house electrical... Then that could be the culprit. Disconnect the charging lead from your kicker battery and see if the problem goes away. IF it does, the charger needs to be checked out (possibly replaced). How many volts is the charger putting into the kicker battery?

Actually... try this first... disconnect the kicker from the battery so that the kicker isn't tied into ANYTHING else. If the problem persists, I would wonder about the anodes you have on it.

[fairdeal]

I have separate starting batteries for each motor and I know that they are not connected in anyway. They never have been connected to my knowledge and I owned the boat for at least 3 years before any of this started. Three Walmart Everstart batteries total in the boat charged by a three bank charger.

The charger certainly has the potential (haha electrical pun) to be the culprit here, whether due to an internal fault or the way it is wired -

but there is no risk - and every reason - to tie those battery negatives together.

And that alone might make the problem go away.

Here's Page 3 of the ABYC Standard E-09 Direct Current Electrical Systems on Boats

upload an image

[DennisG01]

In case I was being a bit misleading, I totally agree with what Fairdeal is saying about tying batteries together. My main purpose was to simply try and isolate the issue directly. Tying them together might very well solve the issue - but I think it might just be faster to get the charger out of the mix, then reconfiguring batteries and running new battery cables... although that may be what's needed in the end.

"potential"...

[chadmyrvik]

Sorry to bring back an old thread but I took the boat out of storage the other day and started to look at my battery set up. Here is what I have: battery 1 and 2 are connected in series for my 24v *****ing motor. 1 also has the kicker motor and a con***** king unit running off of it. #3 runs the big motor and the main breaker for the boat. The neg lead from 1 only goes to the kicker, the neg lead from 2 goes directly to the *****ing motor socket and the neg lead from 3 goes to the main motor and to the main fuse box on the boat. If I understand the previous replies the neg posts on 1 and 3 should be connected but they are not, and as far as I know never have been. The only thing that has changed prior to my issues is the adding a new battery charger, I had to add extensions to the bank that charges the kicker battery. If I used regular copper wire for that instead of tinned wire would that make a difference? I will take all the help I can get with this issue. It isn't fun to have to replace all these parts every month or so when the boat is in use.