Rod,
I bought my boat at Tracy Marine and will never take it back there for anything. I found a great Sanger service shop in San Jose. Top Side Marine.
www.topsidemarine.com . They work on all boats but have years of knowledge on Sanger boats. They will spend the time with you to undersatnd exactly what is going on with your boat. Best of all, they have the best costomer service i have ever had. Reasonable price too.