Separating old kerker exhaust sectiion/baffles?

I've got a Kerker 4-1 pipe that I bought off e-bay. It's in decent enough cosmetic condition on the outside. No major dingsand just a little exterior rust on the inside of the down pipes.
When I got it it was obvious that there was some bad rust on the inside of the pipe. Shaking it up allowed a lot of interior flake to come out. Oh well live and learn I guess. Chance you take on E-bay. I figured I'd at least separate the pipe sections and maybe remove the baffle to see what I had to work with but they are very solidly fused together.
Pipe is on the bike and no amount of heat hammering penetrating oil or twisting will even begin to loosten them up. I'm stumped. I'm considering making small thin lengthwise cuts with a fine grinding/cutting wheel basically lengthening the existing expansion joint where the 2 pipes come together on the outside pipe to see if they'll loosen.

Figured I'd come on here and ask if anyone has solved anything similar before I get that drastic.

Any advice much appreciated.

Yeah, I bought a used MAC off ebay and it was also welded together by internal rust.

I finally gave up trying to tear it apart.

I think you could eat the rust by using muratic acid or similar inside but it would probably screw up the chrome if it gets on it.

Man I vaguely remember when I dealt with this a long time ago too. I took the exhaust down to get ceramic coated and the guy mentioned it was a REAL pain to separate the two pieces. Forgot how he did it, but you could tell the flange got a little buggered up in the process.

I wonder if you could strap the header side to something solid and while applying heat pull on the megaphone? Just a thought.

I had my wife help me with this (you could use a buddy, but without the benefits ) ... pulled the pipe off the bike and suspended it on one set of persons shoulders with the megaphone phone pointed downwards. I then walked around the pipes with a small hammer and a large flat-edged punch and repeatedly tapped downwards on the exposed flanged...eventually it loosened up.

Your small cuts would help, but go ahead and spray PB Blaster or Krolls and let it soak in for 2-3 days. Then (I hope it's black painted?) apply heat. Better to have off the bike so PB or Kroll can work "down" into joint, and makes it possible to apply heat all the way around joint. Get it red hot (the higher heat will expand the metal) and it should come off. If it's chrome it won't look pretty when it's done. :dry: I do all the exhaust at my shop and red hot does wonders for tight pipes/mufflers!

Yeah that's the one downside. The exterior chrome is actually in pretty good shape and I was hoping to preserve it. Well I'm going on vacation this weekend so I'll mess with it when I get back. I think I'll be painting it black when all is said and done though... Damm..

Did you remove the clamp holding the muffler onto the header?

oldkaws4ever wrote:

Did you remove the clamp holding the muffler onto the header?

Yes it's off. Just got back from vacation and I'm going to have at it the next few days. I've mounted it to the engine and I'm trying to get some twist on it using a rubber strap wrench. It simply will not budge. I think I'll be doing some very delicate cutting in the next few days.

Hi Steve, I think your idea of slitting it would work fine. You may want to slit it on the bottom side out of sight, just in case you have to put some weld on it for cutting too far. It's the only way if you want to keep the chrome in good shape. Heat also would work as mentioned, but will ruin the chrome. Good luck, Bob