Just bought this boat and noticed that it usually runs between 150-180 but sometimes it will get up to around 220. The motor is stock with around 200 hrs. The impeller was replaced before i bought it and i just put a thermostat in it. Thinkin of flushing out the oil cooler to check for debris. Any suggestions?

I would remove the thermostsat. 150 is a bit on the high side.