I took my 250 SHO in for the annual service, and this year it was also due for a new water pump. This motor has run like a top for me since day one, never so much as a hiccup. First time out on the water after the service I noticed it was taking a long time to get a stream of water at idle. Eventually - 30 seconds -it starts spitting water, then a steady stream and appears fine. This is longer than it normally takes. I takeoff and all seems fine, water pressure is good.
Then while running later in the day when the lake got some 1-2 foot chop I hear an overheat alarm. I look at the water pressure gauge and it is at or near 0, so I take it off pad and shut it down, the restart and it starts sucking water again and all seems fine. After this I took it back to my mechanic and they thought it might have been a pinched seal in the water pump. They dropped the LU, checked everything, water test it and all seems fine. When I put it on the water again I am now getting the stream of water quickly like I used to but still occasionally lose water pressure, but only when the lake gets choppy. Running on flat water is fine, no alarm.
I just dropped it off at the dealer again so the they can give it a more thorough look. It never did this before the water pump was changed this year, and I've had the water pump changed before without issue. I'm no mechanic, but it seems that possibly the low water pickup isn't working as it should.
Since we have a wealth of educated individuals here, I was wondering if anyone had any ideas? I suspect that they will check the poppet valve, among other things. It's almost like it's an air lock in the system when there is less of the motor in the water (just to be clear, the water wasn't so rough that I was dealing with cavitation or the prop coming out of the water). Seems to only happen when the boat is bouncing around in the chop.
Any thoughts? Anyone ever experience anything like this?