Thanks for the responses - I just spent a bunch of $ getting a new kicker motor, so I'm not excited about spending on a new alternator but I need the batteries in good shape - planning to start hitting the ocean and don't need any problems.

Spare - did you find the trouble shooting chart for the regulator? I do have the Merc factory shop manual but haven't had time to dig into it. About what is a reasonable cost for a kit, if I need to go that way and can I buy it from you and get it drop shipped to me on the left coast?

I'm with Garbubba, 12.2 is gonna leave you stranded. Check the voltage at the batteries with the engine running, don't trust your dash gauge. A good charging system is money in the bank in my opinion.

I agree - stranded is in a car by the road - dead engine in boat is being carried by the current or blown by the wind toward the rocks. Just hoping I can find and fix the problem without having to buy all new, however unlikely that is.

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Usually I do a visual on the balancer. Look to see if there are magnet pieces or whats left of the stator laying around the front of the engine. If the balancer is bad, it usually takes the stator out, if the stator shorts, it fries the regulator. Its been a while since I worked on one, but it used to be $200 per item(balancer, stator, regulator). If its just the regulator, get the CDI brand.

The best charger I still have my son took out of the garbage in Atlantic highlands about 20 years ago, I changed the clips and been using it ever since! Really. It has 2 settings. 2 or 6 amps and 6 or 12 volts. I keep it on 12 volts and 2 amps and use that to charge and maintain my battery's. The only thing that just broke the year is the meter to tell you what it's putting out so I use a multimeter to check it. Still works great after 20 years and might even be longer that that. And cost me nothing. Just two clips so I wouldn't get anything to complicated just a reg charger with different settings will work fine. That's what I would get

That's funny, because I have a backup charger with just those settings. Made by Schumacher I think. Came out of my dad's cellar when he passed away, but that thing is at least 20 years old... (more like 30-40) and it still works when I plug it in.... and yes, the plastic cover to the meter broke last year. I taped a piece of Lexan plastic over the meter to protect it. Just gotta remember that even @ 2 amps you can cook a battery. So I set my wife"s cooking timer and check the battery every 2 hours.

As for the alternator on the motor Id change ot over to a one wire external marine charger that mounts over the water pump and runs with a belt. I bought a new one for 60.00 in the box. Works great! I put my trusty old Shumacher 2/10 amp charger on my batteries about once a month for a couple days on each battery. It charges them up and cuts off automatically.

cfelton, where did you get a marine alternator for $60? I'm seeing kits for $250 - $600.

Spare, thanks for the manual - I'll dig into it and see what I can find.

Had to laugh reading the shop battery charger comments - we could start a historic charger website. I've had a smart charger for a few years that charges at 2, 6 or 12 amps and automatically slows down and stops and an old one that was my dad's (he'd be 104 if he were still among us). I think it's Shauer brand - no meter or anything - if it's humming, it's working, if you forget it and leave it on, you buy a new battery.

Destroyer, these are Optima batteries (the kind that don't have liquid acid). They can't be checked with a hydrometer (www.optimabatteries.com). Looking for an onboard charger so I can just plug the boat in when it's sitting (which is a lot), charge the batteries up if needed and maintain them, I heard that charging at higher amperage shortens the battery life. It's a mystery to me but I want to make the right choice when I replace the Guest 10 amp onboard charger that's no longer working on the boat - the technology is definitely above my pay grade. Reading on their website, I don't see the charging amperage being a problem, but I value the wisdom and experience here so I'm picking our collective brain.

Hey Scook, look on Amazon. I just saw a 110 amp, one wire Delco alternator for 65.67 from Rareelectrical. I used a long bolt that went right over the front motor mount into an existing hole in the head and you can make a top bracket for the top mount hole. Look at my gallery pics, maybe you can see it. If you need any measurements let me know, Ill be home for a few more days, be glad to help you.

power steering pump may get in your way.Keep in mind 1 wire alternators don't charge till you get them over about 1500 rpm, if you do a lot of trolling/low speed idling, you may have issues