I have the MD40B Tohatsu 40 horse 2003 tldi and I am wondering what kind of oil will be required to run through the motor. I have a few unopened jugs of Evinrude premium oil still from a previous motor are those ok or is a specific brand and mix recommended for these? Also, are the $15 a spark plug iridium ngk plugs the only plugs that will work with this motor?