Which oil for 4-stroke?

[captflossman]

What is recommended for a yamaha 4-stroke? I use conventional but is synthetic better?

Thanks in advance.

[robert graham]

plenty of opinions on this subject, but you should probably break in the motor on conventional oil and then go to a straight synthetic oil, change and service by the schedule. check oil often for fuel getting into oil on these 4 strokes. Good Luck!