Risers hot on one side, other normal

I just replaced the risers with a rebuilt set of risers and I replaced the manifolds and risers and now one side is running hot while the other is normal, any suggestions.

 

I assume you checked for water running on both sides?

Are you carbed or fuel injected, gas or diesel?

 

yes water flowing on both sides, manifolds are warm but one riser is hotter than the other, exhaust temperature out of vents are even temp, it is the left side.

 

Carb? Fuel injection (type)?

 

it is a carb system

 

Well, first thing I would do is check for a vacuum leak. Maybe a leaky intake gasket or possibly a vacuum connection.

Since you just changed the manifolds and risers, was the system pretty clogged up? Maybe some crud broke loose and is partially clogging the flow one side?

Have you actually checked the temp difference on the manifolds? They have infrared thermometers now that you just aim at what you want to measure, and it reads the temp via infrared. The infrared thermometer might help you identify if it's one cylinder causing the problem, or the entire bank.

 

How much difference is there? About 20-30 degrees is normal

 

Engine type??

Confused: is this a V8 or similar with two "Sides" or two separate engines??
I've had problems with trapped air in a riser that suddenly cleared after running at high RPM on the water...

 

How can air get trapped in a riser? It is an open system with a high flow of water.