'96 Four Winns Volvo Penta 4.3gl hot riser on one side

[nyy1023]

This year has been such a bust. I had to replace the intake manifold due to improper winterization by previous owner. After replacing the intake manifold I took the boat out for a test run and blew the bellows. I replaced the bellows and when running in driveway I noticed the riser on the left side is hotter than the right side. I also noticed a small trickle of water from the seal of the riser and the exhaust manifold. I took both off to see if there was water in the exhaust manifold due to crack and noticed that there was. After testing I was not able to find anything. Bought brand new gaskets and put everything back together again. After replacing everything there is no more leak but still find it running much hotter than the other. I removed the water hose, drained the water from the manifold in the water ports. Pulled the manifold off to see if there was any water and found nothing.

I hesitate to take the boat out and blow anything again, last time turned into a visit from the Coast Guard, being towed in to a marina and a lot of black smoke from the engine, sounded like a fire in the compartment but nothing but a very hot exhaust system that blew the bellows. Before I do anything I am wondering what else I can do or check.

 

[dypcdiver]

May I suggest you check the Thermostat housing outlets to the manifolds as rust can build up and reduce the flow. When was the last time you renewed the raw water pump impeller, it should be done every couple of years.

 

[skydiveD30571]

It's not uncommon to have different temperatures at each exhaust. I would check the thermostat passages like diver said, and flush the hoses from the thermostat housing to the manifolds just in case. Otherwise, I wouldn't worry too much.