2008 383 Hammerhead Exhaust Risers (both) Hot to the touch

[PigPen13]

Both exhaust risers on my 383 Hammerhead are getting Hot to the touch. I am even getting the smell of something being hot from the engine compartment, however, my engine temperature is reading steady at 160 regardless of RPMs. Looking for suggestions on what to check for and where I should start?..... T.I.A.

[justgary]

3 hours ago, PigPen13 said:

Both exhaust risers on my 383 Hammerhead are getting Hot to the touch. I am even getting the smell of something being hot from the engine compartment, however, my engine temperature is reading steady at 160 regardless of RPMs. Looking for suggestions on what to check for and where I should start?..... T.I.A.

As I recall, my risers get to 160*F, which is easily hot to the touch.  I used an IR gun to measure all of those parts after I converted to closed cooling.  I recommend one for diagnosing this sort of problem.

[UWSkier]

I agree with Gary.  My risers were still hot to the touch this morning 2 hours after I'd pulled the boat and driven home from the lake.  They get hot.  Should be similar to engine temps.

[PigPen13]

I have one and will be sure to take it with me next weekend! Thanks to both of you for your input.  

[Woodski]

@PigPen13 - has there been a change in how hot they are or are you asking a generic question?  If a change, there may be some debris lodged in the water circuit reducing flow.  After you run the boat and they are 'hot' verify both sides are similar.  Note:  if the boat has a list that can induce a differential across the manifolds.  Typically, cast iron manifolds are hot to the touch which is normal for a fully up to temp engine.

[justgary]

1 hour ago, Woodski said:

@PigPen13 - has there been a change in how hot they are or are you asking a generic question?  If a change, there may be some debris lodged in the water circuit reducing flow.  After you run the boat and they are 'hot' verify both sides are similar.  Note:  if the boat has a list that can induce a differential across the manifolds.  Typically, cast iron manifolds are hot to the touch which is normal for a fully up to temp engine.

A very good point.  The most obvious blockage would be impeller damage stuck in the transmission cooler.

[csleaver]

There is a recommended catalyst exhaust re-plumb kit from Indmar for the Monsoon 340 engines that reduces the coolant temperature of the exhaust and increases the longevity of the catalyst.  You may want to look into it.