Re: OMC Cobra 4.3 over heating. New impeller. Still overheats.
Hey curt, boat having exact same issue. I took lower unit apart. Copper pipe looks identical to yours. Even how low the rubber grommet sets on copper pipe.so i think it did not have a good seal.
Keeping fingers crossed.
Did u replace the rubber grommets and pipe or did you just re-use. If replaced then where did u get them?
Re: OMC Cobra 4.3 over heating. New impeller. Still overheats.
This has been very helpful. I have a 96 omc/cobra with a Volvo penta out drive it overheats when under a load. I can put 4 people in the boat and it will get to 200 degrees. I have replaced the impeller, thermostat, checked exhaust manifolds, flushed the hoses on the motor. Could the problem be in the out drive ?
Re: OMC Cobra 4.3 over heating. New impeller. Still overheats.
The main thing with open (raw water cooled) systems is flow in and out. Since they are not pressurized like a closed system they need rapid flow in and out. I will test the water flow in and out when installing a new impeller. Don't forget exhaust manifolds can clog and so cause overheating.
