06' 250 VMax HPDI issue

[fireman158]

I have searched my symptoms with o result.

Here is my issue: Boat was running fine, I stopped to fish and that's when m problem started.

When I restarted the boat there was a screech and the idle was surging up and down. When I got up on plane there was a high pitched whine (like a turbo spooling) so I shut it off. I restarted it when I got home on the hose and the idle rpm is surging up and down.

This motor has probably 1500-2000 hours with no issues till now. Compression is 115 on all cylinders and the plugs look fine. I drained the VST tank and it was clean and water free.

Thanks for the help.

[WALKER]

I have the same motor and only had a screechish like whistling noise before... it happened after I stopped to fish for 30 minutes or so... started motor to go to next spot and motor sounded funny, and did not feel right while shifting into gear. Headed back to ramp and seemed to get on pad and run hard and fast, but made a loud screeching whistling noise... ended up being I blew my lower unit and the noise was the motor because I had lost about all my lower end grease, from what the tech said. But, it was my lower unit.
Did it feel any different putting into gear?