Confirmation to not overfill main oil tank

[rdiesel01]

Once again thanks to this forum in helping me quickly and accurately trouble shoot a problem. I had the low oil alarm go off on my center engine (250xs) I stop the boat and sure enough the under cowl tank is low and not filling. I search here and find out that its likely the block mounted check valve. Get back to marina and change it out - easy enough - start engine and still not filling. While out on water I added oil thinking main tank might be low, which it was not and end up filling it up to the deck mount cap. Now I recalled the thread on not filling main tank above 80% so I use an oil extraction pump and remove some of the oil - BINGO - start the engine and under cowl tank begins to fill. Thanks to Don and the members here for providing useful accurate info

[EuropeanAM]

Just needed some air space that could compress.