6sh cooling question

[New owner yam 6sh]

New owner of used yamaha 6sh. Starts and runs great but no water flow from pee hole after running a minute or two. Immediately shut down. Does thermostat take longer to open / is this normal for this model?

 

[99yam40]

I have never even looked at a 6 hp Yamaha,
But all the Yamaha's I have seen did not need the stat to open to have water come out the tell tail.

You might make sure the passage for tell tail is clear , air pressure blown up it or heavy mono shoved up it
and check water pump impeller, housing, cup, wear plate, gaskets/o rings and up tube