I ended up leaving them on the boat and I did not gut them. Resale value of the part after removal is a very good point.

No experience, but a quick web search lends info on these products:

http://www.marineformula.com/buy.html

http://store.marinebeam.com/unhesive-5200-remover.html

I posted a quick cell phone Utube vid of my exhaust at idle.... search 26ZX idle and it should pop up.... If I need it quiet I can switch to thru prop exhaust..... running at speed around 50 or so you really cant hear the exhaust too good but getting up on plane at slower speed it is pretty mean sounding! TBF

Update. I had 2 separate shops looks at removing the mufflers and both had the same diagnosis, too much 5200 and both said fiberglass repair would be needed. So I did the following. Purchased a few 3 5/8" bi metal hole saws and a heavy duty arbor. Lowe's brand was much more effective than Home Depot's. Burned 4 Home Depot to 1 Lowe's. [ATTACH=CONFIG]543900[/ATTACH] Next I used a 90 degree cutoff wheel and removed the exposed nut and thread [ATTACH=CONFIG]543901[/ATTACH] A 3 5/8" hole saw just fits in the muffler outlets. Using cutting oil and very slow RPM (75-100) on hand drills, I was able to get started [ATTACH=CONFIG]543902[/ATTACH] After I spent a long time on the first muffler I got a system down and averaged 45 Minutes per muffler. Frequent oiling and slow speed was the trick [ATTACH=CONFIG]543903[/ATTACH] The stainless steel is 1/8" thick and a cymbal shaped water diverter was inside [ATTACH=CONFIG]543904[/ATTACH] Inside the mufflers is a coil that when combined with the "cymbal" like diverter route water around the plate that was just cut out. The inlet at the transom to these mufflers is just a shade larger than 3 5/8" so going thru the work of removing the coil is a non-gain in my opinion. Finishing touch is a set of flappers from Hardin Marine [ATTACH=CONFIG]543906[/ATTACH] Would I do it again? On my own boat yes, doing it for someone else, no way.

Rob Looks good. Let us know it sounds. I have removed stock silencers on formulas and is not easy. I usually use air chisel with shim against transom to remove. Have never hurt gel but silencers get damaged easily. I have been running GGB slip in silencers and really like the sound. Kinda like a chambered muffler sound.

Older thread, but wondering if there are any new techniques to gutting these baffled corsa tips?

Faster way this cuts faster
 

https://cimg3.ibsrv.net/gimg/www.off...fd5fe7396d.jpg

Came across this searching for something else. Just use heat and piece of braided fishing line like a worked behind the flanges.