I am looking to purchase a new diesel saildrive for a boat building project.
I am looking at 30-50 hp Volvos and Yanmars. The purchase will be through a established boat builder so we should be able to score an OEM price.
This boat builder has never purchased a saildrive before so doesn't have a ready source.
Anyone have a recommendation for the best OEM price on a new unit?
I'd research the SD20, SD40, SD 50 corrosion issues likely from inferior alloy (the aluminum protects the zinc). Last I checked the Yanmar SD is not isolated from the engine, the Volvo is isolated. The Yanmar prop. is not isolated from the SD on the SD20 (probably the others) so the SD is protecting the alloy prop too. The SD40 had major clutch issues at very low hours. you'll find a number of people who had failures reversing at the dock and smashed their boats. I believe the cone clutch wears prematurely. Not sure about it's replacement the SD50. Several lawsuits against Yanmar. The SD20 oil must be changed every 100 hours and cannot be "sucked up" from the top (ie. you need to haul the boat every 100 hours to change the oil). Enginewise, Yanmar calls out for orange coolant yet their dealers are commissioning with green coolant. Whatever you do don't mix them. Yanmar wants a valve adjustment at 50 hours on the 3ym30. Lastly, I believe both C&C and J boats have both swarn off Yanmars because of the failures and the lack of support. Maybe Yanmar fixed their mess for new customers but they didn't fix mine. FYI:
Posted 23 October 2008 - 06:42 PM public/style_images/master/snapback.png
Peter Johnstone, on Oct 22 2008, 03:36 PM, said:
The Yanmar SD40 drives suffer from slipping clutch cones after 300-400 hours of use, or a long layup. The result is a gear that does not shift into fwd or reverse. We have had 100% failure rates with this model on the Gunboats. We have since steered clear of all Yanmar saildrives, as the newer SD50 suffered similar problems.
Peter, have you had any similar issues with the newer Volvo saildrive? These are built by ZF/Hurth and have a mulit-disk wet clutch like their other trannies. Wondering because I spec'ed one 'cause of the bad rep of the Yanmars...
The patch of non-copper paint around the drive is an interesting solution - think I will try that.