i don't think yanmar
make anything of 100hp or so that goes on to a sail drive. i think the biggest they do is the 4JH series, which tops out at around 50-60hp
we have a pair of 4JH2TE (ie the turbo charged version) and they are good for 55hp or so.
if you cannot come up with a suitable engine
, why not do what we did which was to fit a seperate diesel generator
? we have 6kva MASE, but easy to go bigger.
may cost a bit more but you have enhanced redundancy plus better situation when sitting on anchor