[youick]

Alarm only goes off when idling but is fine running wide open. is my water pump not working properly. If so where is it located and where would this sensor be at.

[rodbolt]

water pump, Thermostats and Pressure control valve maint is annual or every 200 hours WHICHEVER OCCURS FIRST.
just like the maint schedule says.
which hasnt been done on your rig lately?
your describing a typical pressure control valve grommet issue.

[youick]

Where can I locate the pressure control valve grommet. thanks

[youick]

Where can I locate the pressure control valve grommet. thanks

[zzzzz]

you can pull up parts diagrams at yamaha-motor.com...go to the marine section - then parts and service to view the parts catalogs

[zzzzz]

go to the 3rd "cylinder/crank" picture and you'll see it on the back of the motor on the outer exhaust cover