Optimax "beep" at WOT

2008 Optimax Pro XS 225 with 400hrs. ( Don't have serial # in hand, boat is at the storage.)

Been having this happen the past few trips.. Don't really understand.

When I go to open it all the way up to WOT, after about 5 seconds I get a loud "held out" beep, (it's not beeping off and on, just a constant sound.) It doesn't affect anything, if you just keep it down it still turns 6k RPM and hauls rear.

Weird thing is, it usually stops beeping after about another 5 seconds. Something else I've noticed, when it starts beeping, if you drop it down to about 5k RPM, it stops. You can get it back up to 6k, and no beep at all, she justs get on down the water screaming. Water pump pisses normal, full tank of oil, and the motor runs fine with no issues at all. I've been reading up on it a little and some folks are saying it's a sensor in the oil tank that thinks it's low on oil..?

What do y'all think? Thanks!!!

It's letting you know the Yamaha is gaining on you quick!

Jk....

Maybe it's an over rev warning.? Don't know. Water pressure warning?

Well from what I know the rev limit is 6200 RPM, and I've run it wide open plenty of times before and it's never done this.. Water looks like it is pissing fine...

I think that if you don't have a manual for your engine, you should get one - and read it.
I wouldn't dream of continuing to operate an engine with a warning beep issue until I investigated the meaning of the beep, and probably gotten an error code download...
I also think that if you keep making more trips without resolving what's going on, it will eventually turn into something much more obvious, and very expensive....

I see a compressor high temp on my scanner pretty often checking these motors. Check the screen behind the plug next to the tell tell. Oil, water in fuel or overheat alarm would cause the motor to go into protection mode.

But wouldn't "protection mode" shut it down to a limp?? The thing is, it runs perfectly fine and hauls [censored]..

In 2004 Mercury changed the warning horn strategy it only has two different warning non critical or critical 6 intermittent beeps is a non critical and a 6 second continuous warning is a critical. The reason you only here once is it only warns you one time until you cycle the key switch off and on. And also you will not get a warning when you hit the rev limiter. So I would advise you have it checked out by some one that can pull the faults if your getting a warning you storing faults...OPTI

Yes that is what I was saying. Opti is correct in saying the motor needs to be scanned for the warning entry.

That’s the funniest thing I’ve heard in a while

I agree...solid horn is a critical fault. Any qualified Mercury dealer should be able to download faults. Need to have this looked at immediately.