Genset on Beneteau 473
I have a factory installed Westerbeke 8.0 BCDT in a Beneteau 473. It is in a sound proof enclosure in the aft quarter locker, as you suggested. Also as you suggested, it is pretty cramped for access. I am 6' 1", 57 years old and used to be slimmer and more flexible. I did change the oil and filter this summer, and it is doable for me, but not fun. I would rate the difficulty as somewhat less than getting at the steering chains through the cockpitlockers, to give you a sense of it. So, there are other things that are cramped for access in any boat. This genset is not particularly worse. But it is a compact genset, and I would not want a bigger one. One maintainer I respect basically said "some jobs need small mechanics with strong arms". Maybe, if you can afford the boat and genset, installation and maintenance of the gensset are jobs to have done (by strong little people with the right gifts, unless you are one of those). The Beneteau USA factory installed the new model genset in such a way that the enclosure could not be removed at all. I understand they did this to others as well. The dealer cut the enclosure to make it removable (now) for engine service. I assume that the factory is now doing a better job. The wiring, grounding and fusing is pretty complex to think through. So, if you are having after market installation done, make sure it is done well. Hope this helps
