yamaha 115 4 stroke
 

hi could someone tell me a good engine oil other than yammy oil is synthetic oil ok

Yamaha recommends using their own oil. Or a FCW rated oil. On our towboats we use Mobil 1 and have literally thousands of hours on them

hi pete mobil 1 is a car engine oil ?

Yes, a high quality fully synthetic automotive oil is what most run as it is a better oil for about the same or less cost.

the local boat taxi recently pulled their F150's off their boat at 6400 hours, it was written up in the Yamaha bulletin. I don't know what Yamaha said about which oil they were running, but I know for a fact it wasn't Yamaha oil. I think they've run Sierra 10W30 FWC in it. I called Shell oil company once about running Rotella in a four stroke outboard. With in three phone transfers, I was talking to the head of Rotella oil(their customer service is outstanding). He gave me the official spill about them not testing Rotella in any outboards and their sister company Penzoil offers a specific four stroke outboard oil, but after all the official speech, he told he'd run Rotella in it.

I read that article too. Very impressive. even though they said the motors were always run at something like 1500 rpms. At that speed my 225 would probably last that long. Now the motors are on a Grady out in the Gulf somewhere. Like the Energizer bunny...Still going.

I like Mercs and Johnsons. BUT there ain't no way they will make another 1,000 hours let alone 6,400 hours wihout some sort of meltdown..
For the average landlocked boater like me, 1,000 hours is probably 15 years of use. :sun: Impressive longevity.

I run Yamalube 4m 10w-30 and can buy it from a bulk drum. I've always heard use an oil that is made by a company that builds engines and has to warranty them. I do have a friend that uses Amsoil in everything he owns including this f-150. The four stroke oils are sesigned for the higher RPM engines and have anti foaming agents in them.

Hey Pete, they run those engines at 3500 rpm pushing the boat, last trip of the day, they open them up to as fast as its comfortable to blow them out. Ring free in every tank. I ran a compression test and leak down on both engines when they sold them, compression was within 3 psi across all 8, leak down was around 3.5-4 % IIRC.

I've had good luck so far with Castrol Syntec in my Johnzuki 140 4 stroke, it is a synthetic blend.