I need to replace or rebuild 2 Yanmar 3GM30FC saildrives in a 43 foot
sailing catamaran. The old ones are 27 hp with the SD20 saildrive and have
about 3000 hours on them and were submerged in salt water for about 3 days.
Once removed from the water they were taken apart, washed and oiled.

I think I have about 5 options. The first is to have the whole units
rebuilt. Does anyone know a good place to get these rebuilt and what the
cost is? The second option is to replace just the engine and overhaul the
drives myself. Does anyone know where to buy just a new engine and what the
cost is? My third option is to replace the whole system with the newer
Yanmar 3YM30CE version that is 29 hp. I think that this is a bolt in
replacement. My forth option is to replace them with the larger 3JH4CE
Yanmar with the SD40 saildrive. This is the 40 hp version and looks like it
costs about $1500 more each over the 29 hp units. Has anyone replaced the
smaller and older 27 hp unit with the newer 29 or 40 hp unit? I know the
mounts are different with the 40 hp. How much added work and how difficult
is this?

The fifth option is to replace them with other units. Are the Volvo units
identical to the Yanmar units? Can you buy them for a better price? Has
anyone had any experience with other saildrives? How difficult are they to
adapt? What do you think about going to V drives with a conventional shaft
and prop? On all of these I have the option of fixed (about $600 each!) or
folding props (about $1400 each!!!!!) what do people like better and why?

How much more power cruise speed would you expect to have going from 27 to
29 or 40 hp? Most people claim the boat is underpowered with the 27 hp
engines and will do about 7 to 8 knots.

Thanks in advance.
Marg