Tune-up on 7.4 MAG
 

I recently purchased a 1994 Baja Islander 208(Starter!!) with a 454cu and bravo 1 drive. I wanna change the oils in engine and outdrive. Which Oils should I use? I was told by one guy to use 15W40 Rotella. I use it in my Diesel truck and it is great but a boat? Also want to do a tune up any parts better then others?(Cap, Rotor, Wires, Plugs) Plugs I plan on using AC Delco. But the rest I am open to suggestions. Gotta be done by Thursday night. Have big outing on Saturday!!! Thanks Guys for any and all help, I know this is kinda last minute.

Choices for the engine: Merc 25W40, Pennzoil/Castrol/Kendall/Valvoline 20W50, Mobil 1 15W50.

Outdrive: Merc Hi Performance Gear Lube (green stuff).

Plugs: AC Delco (make sure MR's for marine) or NGK's.

Cap/rotor/wires: Merc/Quicksilver or Sierra through various sources on the internet.

I have been running rotella for years on supercharged 454s. It is particularly important to run rotella if you have flat tappet cams. Modern automotive oils don't have the heavy metals content any more to keep the cams alive. You should also add some stp oil treatment to increase metals content further if you run a flat tappet cam. If you have roller cams the automotive oils are fine, but use a good quality oil 15-40.

Many automotive oils, including the Mobil 1 15W50 above have at least 1200 ppm zinc and phosphorus - the same as the rotella (and other diesel) oils.

Thanks Guys I really appreiate the comments. I have owned fast cars and bikes but never a boat. Not that this boat is a fast one compared to some of you guys on this site!!!