At the beginning of the season I changed the water pump in the outdrive as a preventive measure and all was well. After about 30 hrs. on it ( Mercruiser 5.0Alpha 1 Gen 2) we hit some mud and maybe the second or third time that we used the boat after that and at open throttle it overheated. After it cooled down I closely watched the temp. and it starts to climb over about 3300 rpm. Back off and the temp. drops to normal. Even though I changed the therm. near the end of last season I thought I would start there. The therm. had mud on it as did inside the manifold. I flushed all I could and thought this was odd since the boat had been run for some time. There is a drain valve one the front of the block and I got alot of mud out. The therm. felt stiff but changing it did not help. I pulled the boat out Fri. to change the water pump and the impeller looked fine, but I changed everything anyway. I did not have access to a hose at the the dock to check water flow and put the boat back in the water and had the same problem. We were supposed to get a big storm on Sat. so I brought the boat to a friends house and used his hose to flush the motor with earmuffs and did not see any mud and all looked ok. I spoke to a boat mech. and he said maybe a cooler for the fuel or power steering might be clogged. The manifolds are orig. and have about 375 hrs. on them in salt water. The boat is kept in the water and flushed and winterized at end of season.Have you had any experience like this? RR>
