What type of fluid for Evinrude tilt/trim pump?

[Striper80]

I have an 89 110 hp evinrude. The trim pump when bad and I replaced it. I had some Evinrude fluid but it wasn't enough to fill the unit and the nearest dealer is about an hour away. Both manuals I have spec their fluid, but they spec their part #'s for everything else as well. Can I use a generic fluid or should I just bite the bullet and pic up the factory stuff? I do have 2 other OMC engines so it's not like it'll go to waste. Thanks