I have a new O.S. 70 surpass 4 stroke

One guy recommended that I get a tachometer for it since it's hard to hear how rich it's running.

I am going to use a 13-6 prop on it. Now that I have the tach, can someone that knows about breaking in a 4 stroke tell me what rpm I should be looking for so I don't run it too rich?

Any tips on breaking it in?

please reply before winter is over here in ohio

big dan