Temperature guage on 250 yamaha 4 stroke

[John Pro2]

I have a 250 yamaha 4 stroke 2007. The temperature guage is pegged at 240. Does anyone know how to tell if it is the guage or a faulty sensor. Motor doesn't seem like it's hot.

Also, should there be an alarm if the motor is hot?

[Silvertip]

If you bought this engine new, you should have received an owners manual with it. That manual is very detailed in what the indicators and alarms are. You should see red indicators on your tach when you turn the key on. One of those indicators is the overheat alarm.