What weight engine oil in 2013 21EC?

[SBUERGER]

I believe the operators manual recomends 10W-30 or 10W-40 in my 30 HP Yanmar, but my local Yanmar parts supplier recomended SAE30 instead. Can you please clarify?

 

[abcandjrc]

Change Dealers. Yanmar knows what the engine needs and what will give the best service life. Follow their advice. Don't worry about branding, Yanmar would like you to buy theirs at very high prices. But do make sure the SAE/API and other specification numbers/ratings match the recommendation.

And unless you only boat in August in Illinois, the 10W part will be very handy and you will probably never need the 40 part. I.e. go with the 10W-30.

 

[SBUERGER]

Thank you so much for the clarification!

 

[Pearl]

I have a 2010 21EC. The owners manual recommends either 10w-30 or 15w-40. I use 15w-40, because of the higher ambient temperature range of 104 degrees compared to 86 degrees for 10w-30.

 

[knotflying]

I know my 4 BY2 uses synthetic. Not sure if that is required on your engine. If it is, make sure you use it.

 

[captnmunro]

I like Shell Rotella T6 available at Walmart.