Alternators

Andrew_B

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4 Oct 2002
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Wheres the best place to buy a new alternator for a Yanmar 3GM.
I am looking for something with an output as big as posible (ie over 100 amp) without having to alter the mountings too much.
New or recon doesnt matter.

Many thanks

Andrew

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I suggest a local car breakers where you should be able to get waht you want at a fraction of the cost.

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Andrew_B
Not sure where you are located but ry G & C in Bournemouth
Tel 10202 575260 or mobile 0850 737600 they usually do a good deal.

Johna

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Thats the place I get mine from. A fiver each take em off yourself,
Always pick up another a spare as well.

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I have to admit to not knowing anything about a 3GM engine, but what you have to be aware of is the load an alternator will place on the engine when it is charging at its full output. If you do go for something in the region of 100amps plus then you are looking at a power drain from the engine in the region of 4 HP.

Have used a 70amp for the last few years and that covers all our needs, fridge lights, CD player etc.etc. very well.


Phil

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I recently bought a rebuild Bosch 70amps for my 3GM from a starter/alternator specialist for 135 euro. It has the same mountings as the original Hitachi LR135 (35 amps). But, because the 70amps is bigger then the original i had to make a new bracket for adjusting the V-belt tension as the original is to short. Requires longer V-belt as well.
Beware that the alignment of both pulleys it correct or you will keep buying new V-belts.

Although they have about 3000 different alternators on stock i could not find a heavier one that fits the 3GM mountings.

Happy sailing, Steffen

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Just an idea.

I wanted a bigger one too following installation of second battery. The firm instead modified the existing alternator to boost the voltage.

John

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What no-one\'s said so far...

...is that a high-output alternator won't deliver a high output unless your batteries will accept it. Perhaps you have a very large battery bank, in which case it's possible you'd benefit. I have a 660Ah bank of domestic batteries, and I've never seen them take more than 100A, even when I had a 130A alternator with an Adverc regulator. I'd suggest you look at a 70/80/90A unit, combined with a smart regulator. If you get much bigger than this, you really need a twin-belt drive, which complicates the whole thing enormously.

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Check out the model you want and take off a car at the breakers, dismantle and change the brackets of the existing one on to "new" one, if not already the same and at the worst have it serviced by a suitable centre . Costs a lot less than a so called marine one and spares are "cheap"
Regards
Rob

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