I was under the impression that the SD20 was Yanmars 1st generation light displacement
sail drive. To my knowledge, the only Models are the SD20, SD30, SD31, SD40
, and SD50
. I could easily be in error, but I've certainly never seen, nor heard of, an SD15?
In any event, definitely replace all 4 seals
when you get to it as you wouldn't want to haul out
a second time for the other inevitable seal failure.
Here is are two links for identification and servicing the SD20: (There is a schematic compliments of member
SSullivan on page #3 of the first link. Should help with identification.
Yanmar SD20 Sail Drive Caution
Voyage Yacht Owners Association
Have a look at the Gori Props website for folding props.