10-30w or 10-40w for 2006 90horse 4-stroke Yamaha ?

[MATTT]

Which oil should I use to change the oil ? Should it be 10-30w or 10-40w ? It did not mentioned in the owner mannual.<br /><br />Thanks,

 

[JB]

Re: 10-30w or 10-40w for 2006 90horse 4-stroke Yamaha ?

Most 4 stroke outboards call for 10W40, but I would get an answer from Yamaha.

 

[seahorse5]

Re: 10-30w or 10-40w for 2006 90horse 4-stroke Yamaha ?

Yamaha owners manuals recommend 10W-30, and that is the same grade as Yamaha's 4-stroke outboard oil, Yamalube 4M. The Yamaha Tune-up Guide and the 1995 90hp manual say that 10W-40 is acceptable also.