Hello All,
I have a 2004 Searay 280 with twin 4.3 Mercruisers (MPI). Over the winter I swapped a motor out due to water intrusion and now after connecting everything + installing new exhaust manifolds/risers/elbows (dry joint OEM) I am seeing some considerably high temps on the exhaust manifolds.
After initial assembly, I was seeing very high temps on the port side exhaust elbow. It was hovering around 200° F and I believe it melted the exhaust flapper. I replaced the flapper because it expanded and wasn't flapping anymore (blocking the pipe/wouldn't collapse)
After swapping the flapper out, the port manifold was hovering around 171° F and other starboard side was around 163° F.
Are these temps typical at idle? These temps are pretty consistent on a hose & running it in the water. I smell weird plastic/rubber smells not sure if its the rubber boots or paint burning off the new risers/manifolds. What would be a normal temperature for the manifolds to be running at?
I have noticed my motor doesn't come up to operating temperature as fast as the other motor (looking to be a thermostat issue) My question here is, can a bad thermostat affect exhaust manifold temperature? The boat reads 156° F on the "normal" working motor and after about 5 mins of running the "suspect" motor, it only reaches 89° F.
I have read bad timing can cause the excess heat, but the motor runs and sounds great not sure if that would rule that out or not.
Any help is appreciated, thank you!
I have a 2004 Searay 280 with twin 4.3 Mercruisers (MPI). Over the winter I swapped a motor out due to water intrusion and now after connecting everything + installing new exhaust manifolds/risers/elbows (dry joint OEM) I am seeing some considerably high temps on the exhaust manifolds.
After initial assembly, I was seeing very high temps on the port side exhaust elbow. It was hovering around 200° F and I believe it melted the exhaust flapper. I replaced the flapper because it expanded and wasn't flapping anymore (blocking the pipe/wouldn't collapse)
After swapping the flapper out, the port manifold was hovering around 171° F and other starboard side was around 163° F.
Are these temps typical at idle? These temps are pretty consistent on a hose & running it in the water. I smell weird plastic/rubber smells not sure if its the rubber boots or paint burning off the new risers/manifolds. What would be a normal temperature for the manifolds to be running at?
I have noticed my motor doesn't come up to operating temperature as fast as the other motor (looking to be a thermostat issue) My question here is, can a bad thermostat affect exhaust manifold temperature? The boat reads 156° F on the "normal" working motor and after about 5 mins of running the "suspect" motor, it only reaches 89° F.
I have read bad timing can cause the excess heat, but the motor runs and sounds great not sure if that would rule that out or not.
Any help is appreciated, thank you!