Oil Question

[jmcgill89]

This is not a "Which oil do I buy" question.

The previous owner of my GT550 states that he put "Pennzoil Outboard" oil in the tank. And I am fairly sure that's what it is, as it's a nice blue color like the stuff I used to use in my Evinrude. However, he didn't know whether it was synthetic or not. Is there a way to determine if the oil is synthetic?

I have a bottle of Yamalube 2S that I'm going to be using in the Suzuki, and I'm wondering if I can mix it with the oil already in the tank, or if I have to do a total flush of the system?

Thanks,

Joe

[Suzsmokeyallan]

You could remove the tank and drain it and do a quick clean of it and then refill it with the blend of your choice. The oil thats in the system will run through and the new stuff take over as it enters the engine. Keep the oil line to the pump up so it does not get any air bubbles in it, this way you do not have to bleed the system or such.

[tz375]

As Allan said, oils can be mixed.

Outboard oil is not the best, but unless you are thrashing it hard, it is unlikely to be too much of a problem. Since you already have a boat, I'd drain that oil out and use it in the boat motor. Just pull the feed tube from the oil pump and let it drain into a clean container. No need to flush the tank or lines. Synthetic and dino are compatible. No mixing problems.

[Coyote]

Outboard oil is not the best, but unless you are thrashing it hard, it is unlikely to be too much of a problem.

Tell that to Lane P. That's all he uses in his 80+ hp. Buffalo.