SDFever

Mine for some reason, turns the oil jet black only after 1 or more hours of use (not even wot). Started out using Merc 25/40 and then switched to Royal Purple 20/50. Tried changing it twice in a row only after about 8 hours each time and still gets very dark very quick.

It's seemingly way to dark to me but the motor runs perfect. Is it not a big deal?

Also, sent a sample to be analyzed. Came back with generic, vague report from Blackstone Labs in Indiana. Said it was fine with no abnormalities but they could not explain the dark color. Has to be carbon - no?

???????

Hot 4 Teacher

When complaining about how black the oil in my Cummins got so quickly, an old timer told me that "most oil will turn as black as your hat in no time" and went on to say it the color means nothing. I used Amsoil Marine/diesel for a few years and have since switched to a good 15/40 oil, but I'm told Rotella is a great choice too. As long as it's changed at least once a season (50 hours max) and you're not losing any, I'd say your fine. Is your 496 stock? How do the plugs look?

turnerrd

My 03' 496 does the same. I always attributed it to the fact that the early ones run kind of rich and figured it was fuel dilution. I'm glad to hear that your results from the oil analysis didn't show that. I just changed my oil (25 hrs) and was going to get a sample tested. Mobile 1 15/50 syn for me.

Knot 4 Me

My 496 MAG was built in Sept. '03. The oil stays pretty clean even up to the end of the 25 hour intervals in which I change it. I use Mobil 1 15W50. I would think your transom would be sooted up pretty bad if the motor is darkening the oil that quickly.

jswfl09

My oil turns black somewhat quickly. I've never worried about it. After the initial oil changes, the oil has been changed every +/- 50 hrs or so in the last 2 years of its life and I'm creeping up on 500 hrs with no problems. Using Mobil 1 15/50.