I bought a 1997 GTS from a guy that seems to have neglected it. I have to do a few miscellaneous repairs to minor things. Finally took it out today and ran great, until about 5 minutes later I got a overheating alarm. Got to the dock and started checking lines. Both "pisser lines" had good flow but one was very hot. It was the one from the top of the cylinder cover and the water was steaming. I checked the cooling supply lines from the impeller and they all are clear and provide good water flow from the pump. I checked the discharge lines and found some sand in them but I cleared it out and the problem persisted. I also noticed that the engine drain line, which comes from the exhaust manifold, had almost no flow through it. So I flushed the engine. I removed the hoses one at a time to make sure water was flowing out of each one. I noticed that the small one running to the tuned pipe did not have any flow as I was flushing it, but all others did (except for the engine drain line). That being said, I know all external hoses have no obstructions at all. It must be internal to the machine. So my thought process says that I have a clog in the pipe or in the exhaust manifold or the engine. I have good flow coming from the cylinder head cover fitting so I don't think I should look there. That leaves the tuned pipe and the manifold. Can anybody tell me if it sounds like I'm heading in the right direction or not, and if so, is removal of the pipe and manifold a hard job? Any other advice would be appreciated as well.