After spending the weekend in the salt water I was flushing my 1998 Yamaha 150 with fresh water at the house when the temperature alarm went off. I had been running the engine for maybe 5 minutes when it went off and I shut it down just after the alarm when off then I checked the stream of water coming out of the engine and it was hot not hot enough to burn my hand but hot enough to be uncomfortable. Took the cover off and checked the engine and it was hot but not uncomfortable to the touch. <br /><br />The muffs I was using are an older set that were given to me and they only have water coming out of one side. On my engine there is a water intake on each side so I am wondering if I need a different set of muffs? I have flushed it before with these muffs without the alarm going off but this was the longest I have let it run with the muffs on and it was pretty fresh off the water so the engine may have still had some heat built up from being run all day. Would a better set of muffs allow me to flush it longer? Could I have done any damage to the engine by having the alarm go off?