Don't know why?
Charlie: Don't know why any additives that are in the newer oils would effect the seals. But you gave me a clue. You should check out your air filter. Just pull this filter out and wash in warm water and soap. This may be the problem that it is soaked with oil. 2-3 hours of running is quite a while and if you have only run again for 20 mins this may take some time to clean out. I am wondering if the mixing elbow isn't also fouled and it is burning oil in there too. If the filter is clean, I'd check my oil levels in the engine. Make sure that it is full and take the boat out and run the shit out of it at maybe 3000-3200 rpms for 20 mins or so (be sure you don't overheat it). This should clean out the entire exhaust system. If that does not work, you should have the mechanic back over and let him diagnosis this. Tell him the bill is on him, he caused your problem. Good luck, let us know your outcome.
