Warm elbows-440

This winter, I replaced risers, spacers and swivel elbows on my FWC 440s. My first engine was stbd and sea-trialed it, seemed fine. I shot with IR gun all around and temps were good. Top of swivels were 80 degrees and cool. Good water flow out transom. Next did port engine and same thing. No leaks and good temps. Temps at dash were 160.

Problem; started both today and started to see excessive steam from stbd exhaust (at idle) but had good water flow. Felt swivels and were warm (120 degrees per IR gun). Rev'd up a little to increase water flow but only came down 2 degrees. I felt water exiting exhaust and it was hot. Temp at dash was 160+.

I then ran port engine for comparison. No steam, not hot and swivels were 77 degrees. I had to walk away from frustration. Now I'm putting together a plan. Thoughts so I can have a checklist?

Thanks!

Check for any air leaks on the stbd RW circuit. If the system is sucking in air, it will cool less efficiently. Retighten all hose clamps and connections.

Check for a blockage on the stbd side. Use a hose to backflush the system.

-JJ

If water flow out the exhaust is the same on both sides, it could possibly be a t-stat ??

Thanks for the responses. If it were thermostat, would the temp be high or low according to gauge and or the temps taken with IR gun? I did put a new t'stat in when coolant was drained but when engine heats up, I can see temp on gauge go up and what seems to be t-stat opening, the temps come down to 160. Must be new air leak or new blockage. I can see water burlbing in strainer and exit transom, so water is flowing, just not getting cooled.

Agreed on the air leak; you'd be surprised how little of an air leak can cook the engine!

Note: The t-stat has doing to do with exhaust overheating (unless the motor is cooking itself).

Jeff

I pulled end caps off heat exchanger and at the low end, where zinc screws in, I found quite a bit of build up. I started probing each hole and each one a surprising amount of water would then leak out. I began thinking 'this must be the problem.' For kicks and just put the end caps on (I'll be getting new gasket material) and fired it up. Much debris came out wet exhaust and components were nice and cool, just as before. I'll pull caps again for the new gasket material and probe each tube, front to back. I should be good to go!

Thanks again for the suggestions!