My '67 Sea Ray I/O with the above mentioned engine has developed an overheating issue that has me baffled. Boat will start fast and idle perfectly. After 5 minutes or so on the water, engine will not respond appropriately to half throttle or full throttle and basically hesitates like it's starved for gas. Then the temp gauge begins to head from the green to almost the red area. I have to idle back to the dock so as not to make matters worse.
So far I have:
replaced the water pump impeller, tested the thermostat, replaced the fuel pump and filter, use pure 100% gasoline, rebuilt the carburetor, replace the exhaust water hose 2 years ago, made certain the fuel tank is ventilated, and verified that the point dwell, timing and plug gap are right on specs. Awhile back I replaced the ignition coil, water pump and drive belt, spark plugs and plug wires.
I have run out of options to correct this problem. Plus, nobody in my area wants to work on a boat that old. Hey, it's a Mercruiser 4 cyl engine. They should be fairly common.
Could I have a clogged water passage somewhere? Could my new impeller not be working properly and sucking air instead of water? Someone mentioned something about a "melting of a base copper pipe melting in the impeller housing." I hope someone can offer some repair suggestions as I am the ORIGINAL owner of this classic Sea Ray and have kept it in excellent condition all these years.
So far I have:
replaced the water pump impeller, tested the thermostat, replaced the fuel pump and filter, use pure 100% gasoline, rebuilt the carburetor, replace the exhaust water hose 2 years ago, made certain the fuel tank is ventilated, and verified that the point dwell, timing and plug gap are right on specs. Awhile back I replaced the ignition coil, water pump and drive belt, spark plugs and plug wires.
I have run out of options to correct this problem. Plus, nobody in my area wants to work on a boat that old. Hey, it's a Mercruiser 4 cyl engine. They should be fairly common.
Could I have a clogged water passage somewhere? Could my new impeller not be working properly and sucking air instead of water? Someone mentioned something about a "melting of a base copper pipe melting in the impeller housing." I hope someone can offer some repair suggestions as I am the ORIGINAL owner of this classic Sea Ray and have kept it in excellent condition all these years.