Got that right !
8.2 performs very well. I think better than the old 496 I had .
Just a few out there( 2014 yr it looks like ) with some heat issues .

There is some - & some + to having Cats / emissions / 02 sensors in marine gas apps. They have been in use now on the gas side for ten years straight as Indmar started with model year 2006. California started with everything 500 hp and down in 2008 with Cat engines and the rest of the USA started in 2010 model year meaning end of 2009 had them to.

I am not in favor of them but do favor some of the positive sides to them when they are working correctly. Anyways pulling out the CATs - you not find many marine dealers to do this for you plus your engine will not run correctly. The PCM will need to be address by a tuner and I believe there is only one person currently to perform this but here is the problem with changing the stock design and removing the cats- one it voids all warranties and that includes the 3 year / 480 hour all emission and fuel system parts is all voided.

Next is - you will not be able to have your engine work on by most mercruiser trained shops because they are not trained for repairing an engine that has a one off MOD performed that is is totally unstock nor has the experience of this form changed done to it.

There is a unit controller out on the market to trick the PCM to think that the cats are still in place when in fact they have been removed. I do not recommend this either as it has no longevity time put into the field to see any sort of reliability and it plus any damage to engine in the long term side of the coin.

Next, I am real interested in this thread and just started to read the River Daves thread. I see you are there as well. There is some interesting posts over there to say the least. Again not to beat up anyone but B&D on River Daves is the only one I would follow for answers. See the deal with all this new marine stuff is the work by the do it yourselfer has been taking out of their hands and only true completely updated OEM dealers have the best chance to fix it correctly. This is including everything currently, even Merc racing engines. You need so many special tools today but that is the least of it - completely trained properly and experience is the hard part to find. I hate to say but even a lot of OEM dealers are not current. Some are and some are behind and some are way behind.

Just an FYI, I see marine CAT engines now more than any other app in the past couple of years. I do not even have a shop anymore but for 2014 still worked on over a 100 marine CAT engines, mostly nothing as far as a major problem child but yes like everything they do pop up once in while. This still DOES NOT make me the best expert out in the field but at least I know more than most about them and have been to the 3 major OEM marine schools to get trained on them.

Forgot to say that Boat Manufacturers is NOT your best place to get indepth REPAIRS done completely. Most of them are not that indepth or currently trained indepth to do so.

Making boats, rigging and maintenance is a different story about Boat Manufacturers. current indepth repairs and problem solving of these current marine engines Boat Manufacturers should not be seeked out unless a true Merc service REP / engineer is there helping every minute.

Very true is was a teenager back then working in the old mans shop and they were a big problem. I know tech has changed but not so much with marine I do recall running rich fuel mixtures was a big no no back them and marine engine's well they do run rich. Overall i beleive its a very bad ideal very very bad

Any updates ? I just looked over at River Daves and nothing either. Do you have silent choice exhaust set up as the RD problem child 8.2 does I believe ? Post your engine serial # and I can check on any current service updates and or Bulletins about your 8.2.

IMO - you and the other problems of hot one sided exhaust could be a faulty poppet valve assembly, or its restricted (poppet valve),

next - not knowing exactly all the problems of the internet forums 8.2 exhaust overheating problems, I will add to the list as to make sure your air vent downside of the exhaust riser is not restricted and or collapsed nor any part of it including the fitting & hose connections.

Not knowing if water shutters (aka flapper valves) are installed in the Y pipe exhaust including the apps with silent choice - I would make sure they (water shutters) are not causing a blockage or restriction if installed plus installed correctly. If you do not have silent choice the water shutters need to be installed and working correctly plus unrestricted - free of movement.

I would make sure the divider in the silent choice is working properly too and all of that is installed correctly,

next - depending on how hot any of the cats and complete exhaust system including hoses and exhaust tubes got - it might need replacement of all of it with new. I know the one at RD's surely needs everything including possible Y pipe gasket (o-ring) if in fact it is a silent choice exhaust set up not just thru hull or thru side hull. That exhaust system caught on fire.

I am dropping off the boat today for inspection and repair.
Merc the rep. will there this week.looking at both boats.

The exhaust dose not have silent choice .exhaust goes straight out of the transom above water line .
One thing I know is they are going to replace the exhaust elbows with a Merc full radius elbow instead of a fab style. (don't think that is it )

Iwill post some updates

Any updates or problem solvers for either boats on the problems ?

Boat is down at the builders. I hear that the Merc rep. has been down there a few times.
Trying to solve the problems . Nothing is wrong with the engine running . Its the exhaust.
They had water test another boat .
They are working or trying to come up with a solution .Plan B is in the works for my boat .
Just glad it not summer yet .
Must be something with the 2014's .I'm just saying I don't know that. (yet)

PremierPower> That pic you post with the fiberglass discoloration, you should have that looked it .

Send the invoice to the clowns who voted this crap to be mandated. Gov't over reach at its best.