Volvo Penta 4.3GL Starboard Exhaust Riser heating up

[whitebunnyflock]

I have a Volvo Penta 4.3 GL motor where the riser is heating up substantially more on the starboard side than the port side. I can keep my hand on the port side exhaust riser whereas on the starboard riser I cannot keep my hand in place for more than a few seconds. This is after running the boat in the lake for a few minutes especially above 30 MPH. I am assuming my riser is clogged up somehow.

I am wondering if there is a guide somewhere online for troubleshooting this. I have the Seloc manual for this motor but i cannot seem to find this issue addressed in there.

 

[Dave-R]

Pull both sides and inspect. Sounds like they are plugging up. Not a big deal or a big job. Get some new gaskets first. Dave-R

 

[bruceb58]

Make sure the thermostat housing ports that feed the manifolds are free of corrosion. Pull off the hoses and look inside to make sure. Also, if you ever had an impeller lose its blades, they may be stuck in there as well.

One easy test is to pull the hose going to the manifold for a moment to make sure there is plenty of flow to each manifold. If all looks well, start inspecting the manifolds/risers as Dave said.

When was last time you replaced the impeller?

 

[whitebunnyflock]

it was the impeller, it had not been replaced for a long time but i just purchased the boat in February. the one riser still runs hotter but the elbow is no longer melting and temps are well below 100 degrees Fahrenheit

 

[bruceb58]

It is normal for one to run slightly hotter.

Were there any blades missing? If so, search for them.

 

[whitebunnyflock]

there were blades missing and that part is fixed too. Thanks so much for all the help i really appreciate it. I will have to replace this regularly now.