nhtourguide
New member
"Hi, im hoping someone can hel
"Hi, im hoping someone can help me with this one. I have a 1987 Mercruiser 260 in a 19' Four Winns Boat, Alpha One outdrive. Recently the boat has begun to run hot, but not appearing on the gauge. I noticed it when I smelled burning rubber, then when I shut off the engine, the engine dieseled for a minute before it sputtered and finally shut down. I opened the engine cover and it smelled hot and felt hot. Checked the gauge and it was fine but increasing as it sat there. It seems (im not 100% sure) that I can drive at slow speed without a problem, but it overheats when at higher speeds. I replaced the thermostat and the lower unit water pump, but still the same problem. I also removed the hose from the t-stat housing to the bottom of the exhaust manifold on the port side and ran the engine and plenty of water came out. I removed the brass plug on the exhaust riser on the Port side and ran the engine and water came out a few inches from that hole. After I replaced the water pump, I noticed there was considerable more water coming out of the Port side exhaust. Both manifolds feel just about the same temp to the touch. I am thinking about ramoving the exhaust risers to check for obstructions but wanted to check here first.... anyone have any thoughts?"
"Hi, im hoping someone can help me with this one. I have a 1987 Mercruiser 260 in a 19' Four Winns Boat, Alpha One outdrive. Recently the boat has begun to run hot, but not appearing on the gauge. I noticed it when I smelled burning rubber, then when I shut off the engine, the engine dieseled for a minute before it sputtered and finally shut down. I opened the engine cover and it smelled hot and felt hot. Checked the gauge and it was fine but increasing as it sat there. It seems (im not 100% sure) that I can drive at slow speed without a problem, but it overheats when at higher speeds. I replaced the thermostat and the lower unit water pump, but still the same problem. I also removed the hose from the t-stat housing to the bottom of the exhaust manifold on the port side and ran the engine and plenty of water came out. I removed the brass plug on the exhaust riser on the Port side and ran the engine and water came out a few inches from that hole. After I replaced the water pump, I noticed there was considerable more water coming out of the Port side exhaust. Both manifolds feel just about the same temp to the touch. I am thinking about ramoving the exhaust risers to check for obstructions but wanted to check here first.... anyone have any thoughts?"