I have never seen this...reserve oil cap popped

[F31cc]

New to the site and I am looking for some help. I have twin 2001 250 OX's and below is the scenario of what happened:

1.) Left the dock in the morning, full fuel and full oil. Ran 25 miles out, fished and ran 25 miles back. Cruised out at 3500 rpms and came home at 4000 rpms. She ran great....until

2.) I went to dock the boat and I noticed that the starboard motor has oil coming out from the cowling. It was everywhere. I shut her down and took the cowling off and notice that the cap for the oil reserve was off. It looked like it popped off....The cap had a zip tie around it and that was off as well.

3.) I cleaned everything off and cleaned up all the oil and put the cap back on with a new zip tie. I then started the motor and the cap blew again. (oil everywhere)

4.) When I left the dock, I topped off both oil tanks. When we got back to the dock, the starboard tank was almost empty and the port tank was 3/4 full.

Any ideas to what is causing this?

Thanks in advance.....

[99yam40]

transfer oil pump not shutting off like it is suppose to maybe.
are you calling the oil tank on the motor the reserve oil tank?
here is a good troubleshooting guide fo the oil system

Yamaha 200HP Oil Transfer Issues. No automatic Transfer - iboats Boating Forums

[F31cc]

Yes, I am call the oil tank on the motor the reserve....... I will take a look at the info. you provided.

Thanks again.