I don't want to hijack this thread although this is a little relevant. Most marine two cycle engines utilize cast iron sleeves, PWC and outboards etc. There are several companies that manufacture synthetic oil just for marine applications. In fact every Lucas oil sponsored person that I have spoke with is using their synthetic oil in their Optimax/proxs. I also know of a few Amsoil dealers that use their product in this application. Don't you think that if there was a wide spread issue with a full synthetic two stroke oil used in marine applications they would cease to exist?