The merc uses a different system to the Tohatsu in that it only "shows" a tell-tale as when the thermostat opens, its constantly cooling itself, with most of the flow going back down its exhaust. The visual tell-tale will start pumping hot, then reduce as it cools. Perfectly normal but can be worrying to some when they look over and see nothing coming out
Generally it'll show mostly at wot. I'd not suggest removing the Stat, as this regulates the running temp so if removed it'll run too cold, with the usual pitfalls of that coming into effect. If you did remove some people fit a restrictor in its place to slow down the flow, keeping it at the right temp but giving a constant flow. My advise is run with it as per manufacturer with the stat in place. You get used to it
Your Tohatsu does have a stat but is designed to always "show" a flow, as a visual aid. Remember that most of its cooling is still dispersed through its prop/exhaust.
Peter @ Boatsandoutboards4sale ~ www.BoatsandOutboards4Sale.co.uk
~ 07930 421007