I have a 1996 OX66 250hp that isn't using any oil? The tank on the engine is full and the reserve tank was marked with a sharpie to see if the level was dropping and it hasn't moved after 3 hrs of running. I premixed some oil with the gas to ensure that motors were using oil (port is using oil - stbd isn't: the boat is a recent purchase after sitting on a lot for a couple of years) Any ideas? I have not taken any oil lines off yet.

