I'm replacing the exhaust elbow and hose to the waterlift muffler.
The exhaust hose had a soft spot in it that was a few inches below the exhaust elbow and was due to a corroded wire reinforcement. The rest of the hose looked fine. The exhaust elbow was fine as far as I know, but it's a scheduled replacement item. I'm going to have it cleaned up at a radiator shop and inspected to see if it's worth keeping for a spare.
I'm wondering if I should go ahead and replace the rest of the hose downstream of the waterlift muffler. The boat is a 2005 so it's 12 years old, but it looks fine and I don't see or feel any soft spots. It's not surprising that the one bad spot on the exhaust hose was a few inches away from the exhaust elbow, so much heat, and salt water. Not so much heat downstream from the waterlift muffler.
Any thoughts/experiences on that issue?
By the way, I had the injectors (4JH3-HTE) tested with 2,750 hours on the engine and two were leaking and all four were opening too early. I also sent the turbine in and it was fine, no issues, but of course they will replace the maintenance parts and balance it. While I was at it I dismounted the intercooler, engine heat exhcanger and the oil cooler for cleaning and inspection. Surprisingly, the oil cooler had the most gunk in the end caps, but all of the tube bundles were pretty clear.