2018 optimax pro xs running hot at higher RPMs?

[Jimmy3]

I have recently purchased a new 2018 150 hp optimax. I followed the breakin the best I could and I am now just over 5 hous on the motor. I have started getting 6 beeps about 1 second apart and guardian activates above about 4500 rpms. This occurs within the first 2 minutes of rpms above that 4400-4500 rpm point.
With a beep, beep alarm not being a critical alarm I resumed running the boat after checking the both oil tanks. After that outing I took the boat back to the dealer to check for the source of the code. They told me that the starboard temp got upto 178 which triggered a warning alarm.
The dealer checked the popet valves thermostats and changed the water pump. They ran the motor in a tank and said all was good as it's getting 2.5 lbs water pressure at idle and upwards of 23 psi at 5500 rpms.
I took the boat out yesterday and tried it again with the same reaction. I ran over 20 miles between 3500 and 4200 rpms with no issues, about 30 seconds into accelerating to around 5000 rpms the guarian activated again. This time I only had the motor trimmed just out past the vertical position.
Well back to the dealer, their mechanic said the starboard side of the motor got upto 177 and the port was 175. The water pressure had gotten over 33 psi and he is perplexed.
Their mechanic said he thinks I am sucking in air causing my issue and wants to drop my motor down one notch. Does this sound feasible? He said if that doesn't work he doesn't know what else to try.
What I am looking for are suggestions to give to my mechanic if dropping the motor doesn't work so hopefully we can speed this process up.

[lpugh]

What is the water pressure above 4500?

[Jimmy3]

They told me when they hooked up the computer that I was getting over 33 psi moments before the guardian activates but they can't replicate that in the tank. I don't yet have smartcraft gauges so I can't tell you what I'm getting on the water

[lpugh]

2018 and no smartcraft! Thats insane

[EuropeanAM]

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Information with your posts. Thanks!

Very unlikely that you're actually making 33 psi at WOT. Likely you have some pressure leaking into the cooling system, or you have a blockage.

Have printouts of the Run History and/or Freeze Frame (Fault) History?

[Jimmy3]

Sorry for the late response, I've been on vacation the past 10 days. Anyway, i don't have the motor with me as it's still in the shop so I can't give you the serial and exact model number at this moment. The shop called and left a message while I was away and said that they found 2 issues. 1st problem was a piece of what they call the rubber dam was lodged in one of the cooling passages. The other issue was an adapter plate gasket was leaking exhaust into the cooling system. We are waiting on a new gasket to see if that fixes the issue.

Thanks for taking your time to review my issue. It sounds like you hit the nail on the head with your response