Stock Honda thermostats are designed to fully open around 185 - 195 degrees depending on model and/or engine. Many "performance" thermostats are designed to open around 160 degrees. The intention of these low temp. thermostats is to keep the engine slightly cooler, resulting in more power and making the engine less prone to detonation.
We do not recommend installing a lower temperature thermostat because it actually makes the ECU "think" that the engine is still warming up and not fully at operating temperature. This fools the ECU into make fueling, timing, and idle adjustments that are not desirable under normal operating conditions or during tuning.
If you are having trouble with engine overheating we suggest repairing a clogged/blocked radiator, hoses, or engine coolant passages. If this still does not cure overheating, then an upgraded aluminum radiator with a larger core and/or higher cfm radiator fan should be installed.
If you still insist on running a lower temperature thermostat, we recommend adjusting your ECU's programming/tune idle charts and coolant temperature offset tables so that the ECU is not constantly trying to "warm-up" your engine.