4-stroke oil

[CattainD]

I tried searching but I need a four word minimum and oil is only 3. So, is yamaha 4-stroke oil needed or will conventional 10w-30 oil work? I have had a dealer tell me that the yamaha brand oil is not required but he doesn't have the best reputation with yamaha outboards (he doesn't sell yamaha 4-stroke oil). I have a 2001 F-115.

thanks

D-You'll hear a lot on this subject. Many folks prefer to run synthetcis for better protection. Others say use only Yamaha 4 stroke oil. I've also heard the Yamaha oil is a mid grade oil rebranded with Yamaha. The rule of thumb is as long as your motor is under warranty use Yamaha oil. This way they can't come back and give you grief if something happens.

[MrPat]

It's not the oil. Oil is oil. It's the additives. I have had two independent mechanics say to buy a manufacturers oil, Yamaha, Bomb, Merc, etc. They both said it made no difference what brand as long as it was one of the OB makers. They have more stuff in them to prevent rust and other nasty issues. Boas sit for ever unused, while cars are usually used daily. Sitting in a salty, moist environment is a problem for OB makers. Their additives are designed to solve these problems. Oh and run you motor weelky. Tat helps more than the brand of oil.