Yamaha TR-1 Engine Oils?

[Olympus]

I have a 2017 Yamaha boat with twin Yamaha TR-1 naturally aspirated engines. I've been running Yamalube because I was given several jugs when I bought the boat. But I'd rather swap to a full synthetic oil. The manual says 10w-40 with API SJ or SL, but doesn't say anything about using a marine-specific oil. I'm not seeing a whole lot of automotive oils in the 10w-40 weight, but I see a lot of ATV-specific 4T oils that list JASO MA as well as API SL ratings, so I'm wondering if something like that may be the best choice? Super Tech has a 4-Stroke 10w-40 oil that is API SL and also JASO MA rated. I could potentially use that oil in my boat as well as my ATVs. My boat spends most it's time operating in the 5500 to 6300rpm range.

 

[K.Aoi]

I personally run LiquiMoly Marine/PWC 10W-40 in my TR1. I'm not entirely sure if there is a difference but it's inexpensive enough that I'm not worried about it. These engines work hard and are exposed to a rough environment if running in the ocean so I figure might as well get something that is supposedly "designed" for it. Even if it's the same as all the other 10W-40 synthetic stuff it's not like there's a price premium on it.

https://www.amazon.com/Liqui-Moly-M...99&sprefix=liquimoly+marine+pw,aps,151&sr=8-3