Hi there
Mine is gone too on Yanmar yse 8. Tried to put bigger mitsubishi alternator and I just found out this:
According to Yanmar, it takes approximately 1 HP to produce 25 AH of alternator current. At the theoretical "fill load" of a 125 AH alternator, that's about 5 hp out a practical 8 hp Yanmar yse8 diesel.
Mine is 35Ah and this bigger one made my engine very weak. I think you should stick with the same amperage and the rest is not a problem (small adjustment here and there).

Take care.

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