Oil overfill on Brand new Merc 25HP 4stroke EFI

Took my brand new motor out for breakin. Ran it for 1 hour at Various
speeds not exceding half throttle. Took it to 3/4 throttle for about 30
seconds, motor started missing and red light came on. Shut down motor
immediately. Said to myself,what's up now, did the Service Center put any
oil in this motor? Removed the cowl to check oil. As soon as I took dip stick out, I thought I released a Volcano. Oil shot out at me and went all over the engine. I called the service center right away. Told them what happened.
They told me to bring it it right away if I could. Went to the service center.
A mechanic drained the remaining oil in engine. It went past the line in the
tub. He told me that motor was overfilled by the installer. He told me that as far as the missing, He said that the Propeller was not the correct pitch. He said he would take the boat out on the water with a Tachometer, and install the correct Prop. Sorry about being so long winded. My main question is
could I have Damaged the motor after 1 hour of breakin with overfill of
oil? Thanks in advance for an Answer. Needless to say I am not a Happy Camper!

Re: Oil overfill on Brand new Merc 25HP 4stroke EFI

No worries. They come with a "stock" prop that isn't always right for the boat. Run the motor hard to agressively break it in. See Making Oil in the FAQs. The main thing is to aim for the middle of the range on the dipstick. It's different than what you're accustomed to and the FAQ will explain why. Hopefully they've updated the thread. We changed formats a little while ago and the reading was a bit tough in the transition.