"ray lunder" wrote
He had one rebuilt Hitachi 55A model the next size up which is a
drop-in replacement for $300 and has the correct size pulley.
(LR155-31). I get to keep my old 35A as a backup. He didn't seem to
think this would be a big improvement in my case.

ray - This is exactly what we did on our Yanmar 2QM15 - We just use the
internal regulator, and as I mentioned before feed the alternator to the
house bank side of a Blues Seas ACR combiner. When the house batteries are
fully charged, the charge goes to the starting battery.

I was given the 55A alternator but was also sceptical that it would make
much difference. But, I am pleased with the results - I have not measured
the current, but the 200AH house batteries seem to reach full charge quite
quickly.

And, it's easy to swap back to the spare if you have a problem.

With a low horsepower engine, you have to compromise a bit - Maybe larger
solar panel would give you all you need?

GBM