Quote Originally Posted by Plum Nauti View Post
Are the plugs identical in both banks? (Brand, gaps, temp etc) What shape are your hoses going to that side? Rubber hoses can and do deteriorate over time. Maybe blockage in the exhaust??
All brand new hoses last year with my complete overhaul of the boat, only thing I didn't touch mechanically speaking was the engine and the trans, the accessories on the engine are new, new belts, new hoses, new wire harness. Same plugs that I have been running for years, same plug wires that I have been running for years. It ran fine end of April when I put it all together after the winter lay up and then it sat for a month before I dropped it in the water and that was when I cooked the port exhaust hose.

Quote Originally Posted by SquamInboards View Post
So I'll ask you, what problem EXACTLY are you trying to solve? If the mainfold and hoses are ~200 degrees... so what? Annoying though it may be, if it's not causing damage... I'm not sure I'd keep chasing it.
I'm trying to solve the problem that prevents me from being able to use my boat as intended, doing high power/speed runs so I can actually ski behind it. Anything above idle causes the temp to climb drastically on the port elbow and cook the hose and burn a hole in it. At this point in time, I cannot even use the boat for anything other than to keep the trailer or the boat lift from flying away in a breeze. My problem is that my temp doesn't stop climbing with an increase in power and after you get it hot and pull it to idle it takes it 30 minutes to get below 170. As a reference it will go from 115 at idle to 205 in 45 seconds or so and start heating the hose so that I can smell it from the helm. Meanwhile the starboard side is literally ice cold to the touch and I could rest my hand on it and not even think about having to pull my hand. Something is clearly going on because the two sides should only be about 10-20 degree difference between the two and everything port to starboard side is within 10 degrees or less of the other side except for this elbow which is brand new and then everything after it downstream.