My brother has a Sail Drive in a S2 24 ft. Two years ago he needed gaskets as it was blowing water into the boat. I got into the internet & got to OMC although it did not give me anything on the Sail Drive it did give me addresses so that I was able to get to a customer service guy by phone. I was lucky that I got a guy who was familar with the unit & I learned that although it is called a 15 horse power it actually is the 35 H.P. de-tuned. Once you know that, getting parts is not nearly as troublesom. I was able to get a parts book & repair manual for the Sail Drive right from customer service. I think togather they were just over $50.
Walt Ward