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  Topic Review (Newest First)
02-25-2009 09:15 AM
sailingdog Try McMaster Carr.
02-25-2009 01:40 AM
justonemoreproject Thanks for all your responses, know that I have a plan of action I am having trouble finding the parts. Does anyone know where to get a bigger pulley to put on my camshaft? I need a double grooved, 5" diameter pulley to fit onto a 1" shaft. I will also need a 1.5" pulley to go onto my new alternator, as soon as I find one that is. I haven't found a dual footed, small frame, 45 amp alternator yet either!!

02-19-2009 08:43 PM
erps The nomenclature for the small case delco externally regulated alternators is 10DN. I got mine two years ago at an alternator repair shop in Bellingham Washington for $75 IIRC. That did not include the regulator. I just googled Delco 10DN and I don't see any that cheap right now. Here's a hit for $114. An auto wrecking yard would be another source. There were a lot of those alternators built.
02-19-2009 08:15 PM
rocinante33 Justone,

I really like my Leece-Neville 90 amp marine alternator. It was very reasonably priced ($167 2 years ago, if I recall correctly). I think that you should be careful to not put too big an alternator load on your small engine, though. 45-50 amps is probably the absolute maximum that your 7 HP could power. I think 70 amp would be too much for 7 HP.

I think the JC Whitney marine looks like a fair price. It might be worth a try.
02-18-2009 02:49 PM
justonemoreproject I think I will try this approach:
1. Buy a new 45-50 amp alternator
2. Place a 5" pulley on the engine and a 2" pulley on the new alternator.
3. replace batteries with 2 100 amp hour batteries .
4. eventually add a another solar panel.

ANY suggestions on who has the best pricing for alternators? I could not find a Delco alternator with an external regulator for around $100.00.
I did find this one. MARINE ALTERNATOR : JC Whitney: Auto Parts & Accessories
02-18-2009 02:42 PM
justonemoreproject I think I will try this approach:
02-18-2009 01:39 PM
erps Some engines allow you to bolt on different size pulleys, a small one for your water pump, a big one for your alternator. The pully on our MD17 that runs the primary alternator must be 10 to 12 inches in diameter. Even then, I run the motor at a high rpm when its putting out the amps to reduce belt wear. I don't know how hard it would be to modify your bracket to switch to a small case single foot alternator. Perhaps you could borrow one and see how well it matches up?
02-18-2009 01:33 PM
Pulley sizes

One problem is that my alternator works fine on the bench but not on the boat because of the slow Engine RPM. (When at low low idle I can actually count the belt RPMs as the belt revolves! ) The pulled on the alternator is 2.5" and the engine pulley is 3.5" If I went to a 2" pulley on the alternator and a 5" pulley on the engine would that help? There are 2 belts on the engine. One belt drives the alternator and the other drives the 2 water pumps. If I increase the size of the engine pulley, would it damage the water pumps by making them spin too fast?

Any suggestions on where to find a 2" pulley for the new alternator?

My alternator has 2 feet. Can I use a single footed one like this one from JC Whitney? MARINE ALTERNATOR : JC Whitney: Auto Parts & Accessories

Thanks for your help.

02-18-2009 01:14 PM
Alternator and battery choices

Hi John,

Thanks so much for your response. I have owned this boat for 5 years and I don't think the alternator has charged the batteries during that time or the previous 25 years either. The solar panels have been solely responsible for charging the batteries. Originally, there were just 2 grp 27s on board but I was inspired by Nigel Calder to make some changes, but at that time I did not realize that the alternator was not charging.
4 years ago I replaced all the battery wiring; adding a new ACR battery combiner and selector switch and fuses. I also replaced the batteries. I went from 2 batteries to 3 batteries: 1 for a starter and 2 for the house bank. They were 3 year old 85 amp hour gel cells that came from a bank UPS system. My solar charger kept them topped up year round with no problem. (My boat lives in Richmond on the San Francisco Bay where there is lots of sunshine.)

Since the solar panels were able to keep the batteries fully charged, wouldn't if I got 3 new batteries for the bank?

Thanks - Larry
02-18-2009 12:49 PM
erps You can get a standard delco externally regulated alternator for under a $100 that will put out 50 amps or better. You'll need an external regulator which vary in price from $20 for an automotive regulator to a couple hundred for a smart regulator.
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