Muffler for 2003 Super Air Natique 210

It does sound like it overheated first, then melted the exhaust.

The throttling down was probably that the computer sensed the overheat, and was putting the motor into limp mode to keep it from destroying itself.

Best course of action would be to go through the overheating trouble shoot:
http://www.skidim.com/Faq_TROUBLESHOOT.asp#RWTS

I know mufflers can be sourced from Nautiqueparts, but they're expensive, and you don't want to ruin another one.

I was out this weekend to enjoy Labor Day and had a problem after just a few minutes on the water. The muffler on my 2003 Super Air Natique had imploded (the fiberglass did not blow out, but in), a hole about the size of a grapefruit towards the port end of the muffler, on the back side facing the stern, Causing a nasty exhaust leak in the engine compartment. Also, while trying to get back to the dock, it when I would get up to about 2000RPM, it would automatically throttle down to idle speed, and was running a little warmer than usual,about 195 degrees. However, I dropped a few droplets of water on the port side exhaust manifold riser and it sizzled, so it was

The hole in the muffler is directly in front of the electronic control box mounted on the stern wall of the boat, so I am hoping that the hot air and fumes are the reason for the boat not running normal.

The boat has never had any problem like that before, I have owned it since it had 40-hours on it.

The only other thing that I noticed is that the exhaust flapper cover has fallen off, it apparently rotted off at the hinge.

BTW, the engine is the PCM 5.7 liter(350-CI) Chevrolet.

Looking to replace the muffler, does anyone have a factory OEM for sale?
If not, has anyone heard of using Schedule 80 electrical conduit as a replacement?

Has anyone out there had a similar experience and have recommendations for repair?

Thanks,