Stator Problem?

111KAB

Cadet
Joined
Aug 11, 2009
Messages
7
Hello from the UK and thanks for your help again :)

I have a 4 cyl Mariner outboard A104067 (1984?) which appears to have stator problems but I want to try and make sure the stator has packed up before I replace so the symptoms .......

When the engine is running it seems to be providing 'extra' voltage to the battery (16v !!) and I now have two dud batteries but I'm unsure if it is the engine overcharging that could have caused the problem or a faulty battery charger. I don't actually need the stator to work but what I do require is a charged, working battery so as to start the engine and work the tilt etc. I have no problem with removing the battery each time I use the boat and recharging it on dry land however I am concerned that if I buy a new battery and the stator is not working properly it will over cook the battery again so my questions are....

  1. Do you think it is the stator causing the problems or could it be something else?
  2. If I replace the stator are there some other (electrical?) bits I should consider replacing
  3. To save the expense of having to buy a new/replacement stator is there some kind of insert I can place on the stator wire to the battery so as to restrict the voltage to 12v?
  4. If I do need a stator where do you recommend I approach in USA?

Thanks for your help once again and best wishes.:D

111KAB
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Stator Problem?

The stator is fine. Stator provides full current and voltage at idle, and can supply full current at up to about 90V at full speed. So overvoltage is failure somewhere else.

What is the HP of your motor?

Likely, you have either a 9 amp or 16 amp system, with a rectifier. In that case the battery is the defacto voltage regulator. It will use some water, but if you keep up on the maintenance, it's life won't be shortened. If you let the electrolyte get low, it toasts the battery. You must use a wet serviceable battery. The sealed ones will not work.

Your charging system is likely normal.

hope it helps
John
 

111KAB

Cadet
Joined
Aug 11, 2009
Messages
7
Re: Stator Problem?

John - I think your response helps significantly (but if others disagree please respond!) insofar as I don't think (until I inspect) that either battery I have used are wet serviceable batteries but think they are sealed ones!!!

Boat/engine came with no battery so I just assumed I could connect ANY battery - thanks John for your help.

SORRY - forgot to answer one of your queries > 50 hp 4cyl Mariner outboard > THANKS
 
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j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Stator Problem?

I guessed that. It is as I described, and you must use a battery that can be serviced regularly, as the system relies on the battery for voltage regulation.

If you're bent on using a sealed battery, you can Splice in a 20 amp regulator from a later engine. It'll run fine, and put out whatever the stator gives it, probably 9 amps.
 

111KAB

Cadet
Joined
Aug 11, 2009
Messages
7
Re: Stator Problem?

John - firstly thanks again for your continued assistance :)

I assume, whether I use a wet or sealed battery that the inclusion of a regulator is a sensible proposition anyway as this would allow either type of battery to be linked in - correct?

If this is the case I now need to find a suitable regulator > I've checked ebay UK but no luck so any suggestions gratefully received.

Have a good day everyone.

Edit > if I do find a 'regulator' do I link this into the positive (red) feed from the battery to the engine?

KAB
 
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j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Stator Problem?

With the mercury regulator, yelows (2) to stator, black to ground (if present), red (2) to battery, grey to tachometer if present. Doesn't need much cooling, but needs to be bonded to engine ground by mounting.

I'm pretty sure you could rig in a small engine (lawn mower, ATV, etc) regulator fairly easily. Your stator puts out like an alternator, with surplus voltage and current limited by the magnetics.

Just out of curiosity, why don't you just put in the right battery and maintain it? It's been adequate for 25 years. Just a pragmatic thought; Why fix it if it ain't broken?

I engineer things if needed too. I converted my XR4 from 16 amp to 40 amp. I did it because I badly needed the electricity.
 

111KAB

Cadet
Joined
Aug 11, 2009
Messages
7
Re: Stator Problem?

John - are you the only person reading this thread or perhaps you are the world expert on solving my charging problem!:)

Anyway so you fully understand I live in the UK but my boat is in Spain where it sits in a secure garage but unfortunately there is no mains power supply anywhere near. Until I read your initial reply I was not aware the engine needed a wet cell battery as to date I have (I think) been using sealed batteries (modern car type) - what generally happens is that I get to the boat by hire car ~ take out the car battery (don't tell Avis!) and the boat then starts. Once started I run around our bay (or at least the boat does) to hopefully charge up the 'normal' battery. Unfortunately last time I tried to charge up the battery it wouldn't seem to hold the charge so I tried a normal battery charger and again this didn't seem to work. I had a friend test the output from the stator (at the battery end) and as this was running at 16v > 19v he was of the opinion I had 'overcooked' the battery and suggested I needed a new stator hence this thread.

If you are correct (and I have no reason to doubt you) it appears you may have saved me a lot of money as a used stator in the UK is around $200 and I then have to get the thing fitted - so thanks for your help.

All I thought was that if I link in a regulator I could use both a maintainance free battery (from my hire car!) and a wet cell battery. I still have the on-going problem of charging the battery when the boat is laid up/idle but this probably means buying a new battery more often than I should but so be it.

Still having difficulty finding a regulator however so if anyone can tell me where to buy one of these (anywhere in the world!) please let me know and John if you ever find yourself in the Med let me know - the beer is on me!

KAB
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Stator Problem?

You did indeed overcook the battery. A sealed battery can't deal with the unregulated supply. It may also have failed because of local discharge if it's a long time between uses.

You still have the problem of battery maintenance when it's not being used. Why don't you buy a plastic battery box and take it with you when you go home? Put a 1 amp maintainer on it when it's sitting in the pantry, and it'll be hot when you get to the boat.

Eventually you'll get caught "borrowing" the rental car battery. The ECM stores a code when the battery is disconnected.

BTW, if the engine starts readily, you can get away with a lawn mower battery for this scheme. Only weighs about 15 lbs.

Last time I was in the med was dealing with the US bomber crash in Spain in 1966 I think. R and R in Nice was great.
 
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