Re: thermostat
Probably a 1/4 of the older OMCs I see up here (New England salt) have the thermostats removed, and some of them have been running that way for years. So, yes it is done. Further, Mercs didn't have thermostats at all until the mid-1980s. <br /><br />That said, your motor will have a shorter lifetime, use more fuel, and may idle way worse if you pull them. Most modern internal combustion engines run a higher temp thermostat, on purpose, than they ran "in the good old days". As long as it doesn't get TOO hot, a good warm/hot engine runs more efficiently (thermodynamically), & burns off water vapor easily so it stays clean inside. I'd leave them in there for sure.