This winter I’ve converted my DPX drive to a Mercury XR drive. I went out yesterday testing the new drive and now my exhaust risers are turning gold at the tops of both risers which isn’t normal. I measured the temps at a cruise and I can set my hands on both risers. The issue comes into play when the boats idling and the tops of both exhaust risers are so hot you can’t touch the tops. I have the 502 version with Stainless Marine exhaust and risers.
Help!

Same sea water pump?
Anything changed in the conversion?

T stat housing ? does it have the check balls to the manifolds ? It should not

hard to see in your pic that set up and what exactly you have -

The sea pump didn’t change it still has the original Volvo crankshaft driven pump. I didn’t change anything in regards to the engine. It was removed and just the outdrive was swapped.

How is the water flow out the exhaust at idle rpm???
Something changed during the R & R of the engine to reduce water flow.
Hose is pinched, hoses to seapump reversed maybe???

I checked the water flow out of the exhaust and it’s substantial. I checked the the pump inlet hose and it’s free of kinks and doesn’t appear to be on backwards.

1st Things 1st , Replace the Impeller. Make sure you dont have the water hose from the drive to the gimbal housing is not kinked , with the drive down.
Did you replace the houses and cable on the gimbal housing? The Engine turns clockwise from the front , If you water hoses come in from starboard, the top hose should come from
the sterndrive. They will pump some water hooked up backwards.

My .02 How are the temps on the ear muffs? If all OK on muffs you may have a suction problem with the water pump and your new drive configuration. Either not able to pull enough "head" at idle (without forced induction from cruising velocity), or smaller input offices on the new drive not allowing it to pump enough water on it's own. Did you check the hose between the drive and gimble assembly, they have been known to scale or kink. And replace the impeller regardless.
Good Luck.

I’m going to closely inspect the drive hoses and the input and the output hoses to the pump. The crazy part is it’s a simple system.

Hose is pretty we’ll kinked.

I found this hose has a pretty substantial kink in it. The hose runs from the fuel cooler to the oil cooler down by the oil pan. Definitely an issue but I’m not sure if it’s fixed. It appears when the engine was out the hose was set on something.