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Go Big or Small?

PostPosted: Wed Sep 17, 2014 10:34 am
by Rig
I have a 4023-S and a 1023 within a saddle conversion kit (thank you for that tip). With the single belt circumstance we're running, I understand that resistance generated from an alternator capable of producing more than 100A on a 44hp Yanmar could place too much pressure on the Yanmar's water pump bearing. I typically run the engine around 2200rpm and rarely pass 2600. The 4023 is rated to 124A; the 1023, to 105A. Based on the above understanding, I was planning on installing the smaller 1023 as the primary, keeping the larger 4023 as the back up. Appreciating that my understanding may be invalid or incomplete, could you please advise me as to whether my choice to make the smaller alternator the primary a good one?

Thanks in advance.

Re: Go Big or Small?

PostPosted: Wed Sep 17, 2014 7:02 pm
by Coulomb
Some rumors just won't die. The rumor about 100A alternator and Yanmar engine water pumps was started a long time ago but has no basis in fact.

First, an efficient alternator at 150 Amps may be less of a load than a 100 Amp alternator.

You might wear out a water pump bearing if you're using a crummy belt, a very small alternator sheave and you use a crowbar to tighten the belt to avoid slip.

We don't any user of an Ample alternator that has had water pump issue.