2006 496 HO. I’m out in havasu trying to enjoy my weekend. Boat keeps dumping coolant into the bilge. Figured out the coolant was leaking out of the reservoir cap. I’m going to get a new cap in the morning. The boat runs normal temps at idle. The boat also runs normal temps running it at speed, even for 5-10 minutes at a time. After slowing to idle after running at speed the temp keeps spiking way up and then slowly comes back down. Way up like in the 190’s. If the cap is not actually bad could there be an issue with over pressure in the cooling system? Why is the boat running in the 160 degree range at idle and mid-full throttle but spiking way up at idle after mid-full throttle runs? Ideas anyone?