Another Cat Gut- How to...with pics

First let me start by thanking "Oh Whell" for providing lots of pictures during his cat gut. I intend to do the same and give a few extra pointers. Without his pictures, I would have had a lot tougher time deciding exactly where to begin cutting.

First, a picture of what you are dealing with, easiest access is at the bottom, top has a heat shield that is welded in place, no reason to mess with it


Next, I used a sharpie to trace out my cuts, mine were guesses but were just about dead on, rear cut is 2.25" from the shorter plate of the center stand stop, front cut is 1" from where the headers are welded to the collector. It is fairly easy to see the outline of the honeycombs from the outside. Don't get too hung up on measuring the cuts. guesstimate from my pics.


Here is the first cut. Go slow, the cleaner the cuts, the easier the plate will be to weld back on. cut all the way down the the welds near the heat shield.


Second cut, made right where it starts to slope down, a little tricky but again, be patient, I had to switch cutoff wheels at this point.


Here is a detail of where you need to cut down to on both sides and on both cuts.


Now we follow above the weld across to join both cuts. Do this on both sides.


Here is the final step before you will get to see the honeycombs. Grind the two welds that are visible. You will have to grind them down completely until you see the two different pieces of metal. Once you think you ground enough, try prying the piece away, it should feel fairly loose at this point.


Here are two pictures of the plate off after you have ground the welds.

http://i267.photobucket.com/albums/ii291/pjm204/DSCF0347.jpg

Once you have the plate off you need to make two cuts, one on each honeycomb, after you do this the "bridge" in the middle will come off and the two honeycombs will no longer be joined, they should be able to move a little.
Forgot to take a picture of this step....sorry.

Two more cuts will be made at this point. One on each side, this will remove a little more of the "band" that goes around the two honeycombs. After you make the cut, you can hit the weld with a chisel and break it. If you do this on each side, the honeycombs will be free.




Here is what you are left with once you remove both honeycombs.


The plate should fit back on nicely, ready for welding.



Now we are ready to weld it all back up.

First I cut a piece of stainless to fill the two holes. I then used clamps to bend it to shape on the inside.








Now I cleaned up all 4 sides and put it in place ready to weld it up...tack first. Let me warn you, I am not a welder. I took a few welding courses and used to be decent at it but that was also using a very nice miller mig welder. I used mild steel wire and a 75/25 argon/co2 mix. I should have used 100% argon and stainless filler, hence the ugly welds. I may grind them down and get the headers jet hot coated.

 

here kitty kitty

 

LOL


Nice job pjm! I think this will be a good resource for future cat-killers.

 

looks like ( and thanks for the great pics PJ ) you can use the case of the cat as a jig to make a Y pipe, you just need to cut it back so you can have access to the exhust pipes.
tack weld the Y to the pipe openings and then cut the remaining cat housing off
done deal.

 

pjm204...

Thanks for taking the time to do this, nice photos and explanation... good job!

Paul

 

Twas my pleasure....

 

definitely avoid the paint and then wrapping...
those pipes get red hot under the wrap, the paint will burn up real quick...
i wrapped my motad, but now im thinking i want to get them coated in flat black....

 

Nice job pjm204, very neat and tidy. May have to look at this if I don't get some aftermarket headers.

 

What effect did this have on the performance?

 

I haven't put it on yet, I assume it won't have as much affect on performance as I'm hoping it will.

BTW I ground down the welds....

 

PJM204 please let us know. Also if the bike runs cooler in traffic.

 

I was gonna say grind the welds down.......it looks ghetto if you don't

 

Well, maybe he lives in the ghetto!