I just did the cans on my 2001 M750 and they were different than some of the other cans I saw in the other DMF tutorials and vids. My stock cans had 3 internal sections, with the baffles sectioned off with cross over tubes. I took a couple pics and can post what I have later tonight. My process basically took the stock cans...dismantled them....drilled out the spot welds that held the baffles in...pulled the baffles out.....and put it all back together. The mufflers look the same as they did before I took them apart....same length and everything.
Here is my process(i'll add some pics later)
1. Of coarse...removed mufflers from the bike.
2. Using a rubber mallet...hammered on the pipe where it connects to the header, while holding the aluminum sleeve with my hand...this slid the alum cover towards the header end of the muffler. This will expose the factory weld of the end cap to the muffler body.
3. Used a cut off wheel to cut thru the muffler body at the end cap weld.
4. Now...there is a 1.5" tube that exits the end cap...which connects to the baffles....you must slide a hack saw into the cut you just made in the body to cut the tube off. Your end cap should seperate from the muffler body at this point. There was some steel wool like material in mine(flash back material). I removed it and threw it away.
5. Now......you can slide the alum cover towards the newly cut off end. First you will notice the folded end will not go over the rest of the oval can. Being really careful using a wide pry bar.....I carefully bent that part of the alum can up....just enough to go over the rest of the oval can. You dont need to bend this part up much.....just enough to allow it to clear.
6. After removing the alum cover.....you can now see all the factory spot welds in the muffler body. If I remember correctly....there were 6 or 8 spot welds you need to drill out. I center punched each weld...then drilled out with a nice tit step drill bit. Make sure you drill the welds out completely.
7. At this point.......you should be able to work the 3 chamber baffle out. You may need to get some vise grips on inside to pull it out......but it will come out. Also...the end cap will have the smaller 1.5" outlet inside the larger 2.5" pipe....you can pull the smaller tube out also...nothing is holding it inside the end cap outlet. If you want to keep it....you'd have to weld it to the end cap.
Note:These pics are only showing the 2 baffles..there should be one more between the end cap plug. Left in photo is to header pipe.
8. Now with all the baffles removed....take the alum cover and enlarge the mounting holes(oval shape is fine with a dremel) towards the header pipe.....slide the alum cover back onto the muffler body....all the way to till it hits the pipe.
9. Position the end cap so it lines back up with the muffler body and reweld to the can. Be sure to watch that the end cap is even and square as the weld heat wants to move it. You may have to grind down your new end cap weld some.....just to make the alum cover slide back on easier.
10. Slide alum cover back into the stock position and using the rubber mallet you can easily tap the folded section back down to match the part of the can.
11. Reinstall on the bike.
I originally did just a partial baffle removal.....bike sounded/ran better than stock, but wasnt what I wanted still......so I took it all apart again and completely removed every thing from the inside and got the results I wanted. Also.....I have a couple vids of the bike at stock...partial and complete removal I will try and post later also....so you can compare the differences.
