How to install aftermarket exhaust

Pardon my complete ignorance... never worked on exhausts before, and haven't taken the old one off yet.

As I've posted before, my bike has an aftermarket 4-1 exhaust on it with no baffles. I bought a new Mac 4-1 exhaust system that isn't rusted and is hopefully quieter, but I want to make sure I have everything I need to install it.

The new system is just two pieces of metal that slide together, and some mounting brackets. I thought there were usually gaskets between sections of exhaust pipes, but it didn't come with one so I guess it doesn't need it?

From reading about it, I think there are copper gaskets where the headers connect to the exhaust manifold. Currently, I'm thinking I just need to replace those gaskets and the 8 mounting studs and their nuts. Sound right?

Thanks!

 

dont have this set on my xj, but by the looks of the pics i see on the internet, there should be some sort of hose clamp or coupler that would clamp around the joint of the 2 pieces.

that being said, i would for sure get a new set of crush gaskets to put on, to ensure that you have a good seal. And since nobody else chimed in yet, be super careful when taking the studs off the manifold, as you dont wanna snap one off. I highly recommend PB Blaster for penetrating oil; have had good luck with that in the past. Good luck

 

dont have this set on my xj, but by the looks of the pics i see on the internet, there should be some sort of hose clamp or coupler that would clamp around the joint of the 2 pieces.

that being said, i would for sure get a new set of crush gaskets to put on, to ensure that you have a good seal. And since nobody else chimed in yet, be super careful when taking the studs off the manifold, as you dont wanna snap one off. I highly recommend PB Blaster for penetrating oil; have had good luck with that in the past. Good luck

 

It does have a clamp to keep the sections together, I was just also expecting a gasket or something.

I saw that chacal sells an expensive "broken stud extractor" tool, so I will be very careful Everything I have taken off so far has been in good looking condition and came off easily, but I'm still soaking everything in PB Blaster before removing and then replacing with new ones.

 

The MAC systems do not use a clamp or gaskets where the muffler inlet fits into the "collector" outlet pipe........strange but true!

 

and then one day you hit a bump on a bridge and modiy your exhaust to an open header.....

don't ask how I know.

 

Put the System on and get it "Fitted"

Once you have it on there and everything is Lined-up, ... MARK how the pieces fit together with a Sharpie.
Make sure that there are NO "False Lines"

Drop the System and go have it TACKED together at several points with Welds that will be easily CUT through if you need to disassemble it later.

Bring it back home and spread a folded blanket on the floor.
Bring in the Bike
Slide the whole System under the Bike and hang it with somebody helping you do the twists and turns.

 

i have a supertrapp on a mac pipe with no clamps on the intermediate
pipe
if the muffler can't go back and the pipes can't go forward how can it fall off
the mac muffler went over the collector 1.5 inches, getting it off is the hard part
if your really worried about it drill a hole through them and put a sheet metal screw in it

 

I'm not currently worried about it at all, just wanted to make sure I have the right parts. If I get it on and it looks like there's any way it could possibly fall off, the tack welding is a good idea... assuming I can then get it back on as one piece.

 

The collector goes inside the muffler. There's a couple inches of overlap.
There must be some kind of clamp, that's even further out.
The exhaust heat expands the collector MORE than the muffler pipe,
and more than the clamp. It's self tighening.

Loud mufflers can be packed with a variety of materials at home, just to take the edge off, or go real quiet.

 

http://www.mcmaster.com/#hose-and-tube-clamps/=78gfen
i was going to get some of these but don't think it's necessary
besides, i'am just too cheap

 

Best I could gather from mine was that the mounting bolt on the muffler came off and then the can slid off the pipe.

 

I got the new Mac 4-1 system installed today. Sounds much better, seems to have cured the lean condition, and looks great! The only problem is it didn't fit perfectly, the muffler hits the rear brake lever and the center stand.

I managed to bolt it on in such a way that it is stretched out to the side a bit and doesn't contact anything... I'm hoping that after some riding the metal will take the bend with a little less strain. I didn't end up using the RTV sealant because the angle problem made it really hard to mount. I should have done that before mounting the headers. I didn't test for leaks yet, but the improvement is so huge that it hardly matters.

 

Some of those 4-into-1 Exhaust Systems require a "Center-stand Delete"

 

The Mac 4-1 that I have enroute is not supposed to require center stand removal. I hope this is the case as the Kerker that is on it now did and I really want to reinstall the center stand. Not to mention that I have to drop the exhaust to change the oil. Another reason I ordered the Mac as they claim it will not interfere with oil filter access.

OP You did it right. If you had mounted the can/collector first there is no way you would have gotten the header conections to line up.

 

I pulled the pipe as far out from the bike as I could, and then used the S-shaped bracket that came with the Mac exhaust to bolt it there. It was under pretty heavy tension and I torqued the bolts down hard to keep it in place. I don't think it's in danger of breaking or anything like that, but definitely not where it wants to be. In the spot I have it, though, it doesn't touch the center stand or the brake. It might block the rear axle from coming out, I forgot to check.