I am wondering about switching to synthetic oil. What I want to accomplish is alittle less smoke and load build up. Mainly because this engine spends alot of time trolling (1 to 2 hours at a time). This 2001 40 hp 3 cyl, bought new in 2002, runs very well with no complaints. Idling extended times with any 2 stroke, my guess can create alittle load build up. Once I open it up for a minute or two it clears out again and will idle for extended periods smooth again. Running good grade tcw3 currently.