I use Amsoil interceptor in my 09 Dragon. Just pulled the exhaust valves to clean and never had to scrub them, very little buildup. Have been using this oil for years. Used it in my 03 754 rmk mod with over 5000 miles on same jugs, crank.
Shell Synthetic.......................Figure they know a we bit about oil.Price is right as well.
Only motor I ever blew was ran strictly on amsoil,figured it was time for a change.
catmando!