calincoltsdad
Seaman Apprentice
- Joined
- Jul 17, 2009
- Messages
- 33
My 4.3 V6 yamaha was overheating when I found there was no thermostat in the engine. I put a 160 in it but the temp. was still going up to 180-185. Service center said it should have a 140 therm. in it. Ordered a 140 but haven't got it yet. I found that if you open the petcocks on the exhaust manifolds while its running the engine doesn't run hot. Why is that? Is the water going in the exhaust manifolds only there to warm the engine since it bypasses after it comes to operating temp through the risers? Would it hurt to run hoses from the petcocks to the rises and Tee in and run the engine? Also I have more water flow from the drivers side manifold than the other side. Could there be an obstruction?