What brand oil do you use in your Yamaha 4-stroke?

What brand do you use in your 4-stroke? In the past I have used semi-synthetic but I was told I should just use regular? What do you use and why? What is the brand favorite?

Use Yamalube or any other high quality marine 4-stroke oil, It has anti foaming agents and rust inhibitors made for running a 4 stroke at such high rpm’s.

I use AMS oil used it for years in every truck car boat. keeps the compression good and lasts longer then conventional. I fish late season through winter help it turn over easier. Best on market IMO

Rotella 15-40, same in my Suzuki F50. All my engines, gas and diesels use the same thing. I keep 4-5 cases on hand, it’s less confusing this way. jerr

p.s.my F115 has over 1000 hrs, and the F50 is working on 400, I’m a firm believer in early oil changes, seems to work for me.

Been running Yamalube for the past ten years with no problems.I don’t have any personal experience running with synthetics in outboards.

I have used Amsoil in everything that I own for years.

mobil 1 550hrs and hasent missed a beat

I have used nothing but the Yamalube for the last 8 years. Goes in clean comes out clean. I think it is just good insurance to follow the manufactures recommendations for oil service intervals. I have replaced several auto/truck engines that have used all brands of syn oil that people thought they could save a few $$ and drive forever without changing oil and filter.