… or is it just noise
I know not a thing about Yanmar
SD-50 sail-drives and have no experience with them so any information you can offer is appreciated. I have read a lot of Yanmar
documents and hundreds of internet
messages and long threads about Yanmar sail-drives.
The information I receive from seemingly credible voices is contradictory and confusing.
we are trying to buy has a pair of 2005 Yanmar 4JH3-TE (75HP) engines which each power a Yanmar sail-drive. The engines have about 2400 hours on them.
In July 2014 the current
owners replaced the original SD50s with new Yanmar sail-drives. I am trying to determine if they put in SD50s or SD60s. The owner is out of the country and I need to get permission to board the boat
again to look at the drive units. I have not gotten a straight answer about the reason for the sail-drive replacements
I talked to the owner of a large boat
brokerage. He says they have sold
hundreds of sailboats, many of them new, with SD50
sail-drives and have had only one warranty issue. That problem was caused by the failure of the boat owner to keep zincs on the sail-drive.
I read hundreds of postings on the internet
about all the problems owners have had with their SD50s but then the boat dealer tells me they have never had a problem.
I see posts on the web where sail-drive owners claim that when the SD50
is properly maintained they are reliable and then I see some owners claim they have had the same problem with three consecutive SD50 units.
I also see that French boat builders are now putting only sail-drives in almost all their monohulls, catamarans, and many of their fast trawlers which seems to be a real vote of confidence.
Now, I find an August 2013 Press Release from Yanmar that seems to say they are replacing all SD40/SD50 units with a totally redesigned SD60 including a dog clutch
and better oil seals
. That seems to be a real vote of NO-Confidence.
Are the Yanmar SD50 sail-drives a potential problem or are they a stable and useful drive unit when well maintained?
A second question is about oil
changes in the Yanmar sail-drives:
I see that Yanmar makes a pressure system to force oil out or a suction system to pull it out. The local dealer tells me that neither works well and they recommend that the oil only be changed when the boat is out of the water
and the lower drain plug
can be pulled and gravity lets all the oil drain out.
That sounds like an expensive option in a 51’ catamaran
with a 28’ beam, which costs $600 to $1,000 to pickup here in San Diego
. Changing the oil every 250 hours or once a calendar year at a cost of $1,000 means the sail-drive costs at least $2/hour to operate (a pair of engines) or twice the sum of all other operating costs.
Is it really necessary to haul the boat out of the water (or put the boat on the beach on it’s keels) to change the SD50 sail-drive oil?
I do understand that I can change the oil when I paint
the bottom every third year but I am concerned about the times we are off cruising and put a lot of miles on the boat.
A third question is about motor
The Yanmar Sail-Drive operation manual says:
NOTICE: When sailing, set the remote
control lever in neutral. Not doing so WILL
introduce slippage and void your warranty.
NOTICE: Running for long periods at low
rpm with the Sail-Drive engaged can cause
slipping and premature wear of the cone
Those two statements seem to prohibit motor
sailing. I have read a number of internet messages that describe the problems caused by motor sailing when the wind
or wave action is strong enough to cause the boat to surge ahead of the thrust provided by the sail-drive.
When we are passage
making in our 40’ cutter
we motorsail a lot when we cannot maintain a 3-knot sailing speed. We frequently are able to make 6 or 7 knots motorsailing with an engine
speed 500 RPM
lower than with no sail.
Is it possible to motorsail with SD50 sail-drives and not damage or cause excess wear on the clutch and drive shaft?