This UOA is from a Mercruiser Bravo 3 outdrive, ~30 hours on the oil, ~200 hours on the drive. Oil is unknown, boat is new to us (we have one season with it). Any comments about the heavy oxidation on the oil and insolubles? There is a chance there is a lot more than 30 hours on the oil since the boat is new to us. But, the port drive UOA came back better. Boat is a 2003 Formula 330 SS with twin 6.2L w/B3's. We changed the oil and are planning to resample after the summer.

"The starboard unit is wearing well, too. Iron and copper are a touch higher on this side, but iron is
still well below the average, and copper isn't high enough to mark or show trouble. It looks like this unit isn't
struggling with any mechanical issues. The oil is heavily oxidized though -- note the high insolubles reading.
We didn't find any contamination that might be to blame for it, but maybe excess heat caused some
oxidation. The oil's viscosity is in the 80W/90 range. Check back on insolubles next oil change. Hopefully
the high reading was only temporary."

ALUMINUM 4
CHROMIUM 1
IRON 102
COPPER 19
LEAD 2
TIN 0
MOLYBDENUM 108
NICKEL 1
MANGANESE 1
SILVER 0
TITANIUM 0
POTASSIUM 1
BORON 11
SILICON 4
SODIUM 24
CALCIUM 1925
MAGNESIUM 11
PHOSPHORUS 477
ZINC 18
BARIUM 0
SUS Viscosity @ 210°F 70.5
cSt Viscosity @ 100°C 13.09
Flashpoint in °F 450
Fuel % -
Antifreeze % 0.0
Water % 0.0
Insolubles % 1.8

Under sustained cruise speed , Bravo drives are well known for building extreme heat. A good drive shower helps greatly. Good luck with boat!!! W

Thanks, we will take a close look at the drive showers, it has factory installed units. The other drive's oil was fine. The shower hoses look a bit kinked. Maybe one is flowing less than the other.

If u didn't have drive showers the oil would come out the viscosity of water and black as black. I put showers on mine and that stopped right away, now lm just getting dirty oil to be cleaner after each change. 28ss w 350 mags