I have a 22' seasport with a volvo 302 fuel injected motor. Last year one of the heat exchangers plugged with scale and heated the manifold to where it cracked and the rubber couplers to where they were quite crispy. I have replaced the manifolds and heat exchangers with new ones and the right side (from the back) heated up much more than the left side. You can see much more water coming out of the left side. The right side looks more like a heavy mist compared with actual water coming out of the good side. I replaced the impeller in the water pump but have yet to run it to see if this helped. The temperatures with a laser temp gauge is the left side is at 73 degrees and the right side around 130 degrees. My next move is to check the water outlet at the transom to see if this might be restricted possibly because of the scale that initially caused the failure.
Any thoughts or if anybody has experienced this would be greatly appreciated.