Oil for Yamaha 4 stroke 90 hp

[ellissg1]

Does the oil have to be changed often, even if I use the expensive synthetic stuff?

Does Yamaha make a motor where the oil does not have to be changed, just topped off?

Please reply to my email.....ellissg1@att.net

[rodbolt17]

so far, no one has invented magic oil.
depending on your area you can most likely use any marine rated FWC four stroke oil in a 10w-30 or a 10w-40.
some use synthetic yamaha doesnt specifically recommend it.
they do recommend changing the oil at 100 hr or once per year intravels.

[99yam40]

Does the oil have to be changed often, even if I use the expensive synthetic stuff?

Does Yamaha make a motor where the oil does not have to be changed, just topped off?

Please reply to my email.....ellissg1@att.net

Buy an old 2 stroke and just add 2 stroke oil if that is what your are looking for instead of a 4 stroke