hi,was cruisin lake mich.last weekend was in some semi rough water all running well,hit a couple high wakes off another boats wake and wam looked down and water temp shot up to 225 deg. and guage red light popped on.I shut down asap,felt heads,exhaust mans,and felt cold from the lake water,no blown hoses,water psi was in norm range, restarted engine temp shot down to 160 range and rest of cruise was normal. what could cause this kinda problem? 97 502 mag stock (except stainless marine manifolds) recent change of all cooling hoses, raw water impeller, belts, this season (therm 2 years ago)? all other cruises normal this season.

The guage is probably starting to go bad. I had Gaffrig redlines that would do about the same thing. It eventually got worse and happened more often. Replaced guage and all was fine.

You might also look for corrosion at the main engine harness plug on the engine and also main harness connector under the dash. Probably the gauge though