Used Exhaust? + How to remove old exhaust?

I found a set of Midnight Maxim Exhaust Pipes used on ebay just 80 miles away. The midnight maxim only came in 650cc, right? And so it should fit my XJ no problem, right? It's a 4-into-1, and has some rust, but seems to be in decent condition. The price is right, anyways.

Anything I should know getting into this?

 

Re: Used Exhaust?

I've got a 650 Midnight (1981). As far as I am aware, the Midnights were only 650's and 1100's, and ALL came with 4-into-2 exhausts, with all four headers joined under the engine in one of two ways. I don't recall ANY being stock 4-into-1 (though I could be wrong, please wait for confirmation from one of the gurus).

IF it is an exhaust from another 650 Maxim, it SHOULD fit. If it is from an 1100, I have no useful knowledge on that subject.

The stock exhaust on my 1981 650 Midnight was a 4-into-2 with tapered mufflers on each side, and rubber stops for the center and side stands.

Hope this helps!

 

Re: Used Exhaust?

Howdy, GURU here, there was a midnight Maxim in the 750 size but I believe it was 1983 only.

 

Re: Used Exhaust?

This is a picture of the exhaust. This would impede airflow a bit on mine if I'm going from a 4-to-2, right? Which would have the opposite effect of straight pipes, and 'richen' the mixture a bit?

 

Re: Used Exhaust?

None of the Midnight models had a 4 into 1. That's a aftermarket exhaust, it will fit though if the seller isn't fibbing about what it came off of.

 

Re: Used Exhaust?

I'd skip that. It's not original.

 

Re: Used Exhaust?

Hi Fintip, all of us "gurus" agree that you should not pursue this purchase if the seller has implied that this is a stock exhaust. We are watching out for the newbies.

 

Re: Used Exhaust?

I don't see that the seller ever tried to state that it was stock, just that it's what he got it off of. I wasn't ever under the impression that it was stock. That aside, is it still objectionable?

On a related but separate topic:

I'm currently trying to remove my exhaust, and it's really difficult, I'm not quite sure how to move forward. Do I have to take the headers off? It looks to me like the kickstand bracket makes the rest impossible to pull back...

If I take the headers off, do I have to replace the header gaskets?

 

Please, anyone, I am kind of stranded until I get this done, and I'm afraid to move forward without advice because I know those exhaust header studs are a nightmare if they break...

 

Replace the gaskets any time you can.

 

can you post some pictures? What exactly is the issue? Perhaps find out who else on this board lives near you and send them email?

 

hold off on those pipes, their patched and not even patched well.
that's not a skid plate on the bottom pipe

 

Good to know polock.

As far as the exhaust, I just want a how-to on removal. What all do I need to order? If I can get away with just taking off one half, left side only, then I'll do that--I have two head-to-header gaskets already that someone gave me, that they didn't use, so that should work...

I'm just afraid of removing those studs, I guess. Those nuts are damn rusty... Really don't want the nightmare that is a broken exhaust stud on these bikes. I saw a triumph at the motorcycle co op the other day. He mentioned how the only thing rusty on his bike is those exhaust studs. I went to look at them... Must have been 4 or 5 times the diameter of ours. Serious design flaw as far as durability goes, making them that small...

 

Re: Used Exhaust? + How to remove old exhaust?o

Soak them overnight with penetrating oil (preferably kroil if you can get it)

Order some studs from xj forever just in case...they are cheap enough

 

I have a question, how do I get the red rust marks off my exhaust

 

Fin,
I have removed my entire exhaust by myself, couple of times. Once was out on the street, in front of my house, with just the side stand holding her up. Its not too difficult.

If I remember correctly... First, loosen the claps that secure the headers to the collector. Then remove the hardware that supports the mufflers. All you have to do then is just wiggle it free.

Next is the headers. If you are having difficulties with the header nuts, I'd suggest a liberal application of some sort or rust breaker(PB Blaster something of the sort). Douse it good and let it work over night. Consult your manual and carefully use a torque wrench to break it free, while being sure not go to much past the suggested torque value. Maybe even try get your hands on a low torque adjustable impact wrench. Once you get the nuts off, just wiggle them out. Start with the out 2 headers so you can then turn the inner 2.

You may want to break the header bolts free first so you dont waste your time with the other work. The hardest part, for me, was trying to aline all 4 headers to accept the collector when putting them back on. Again, I was working alone...

Good luck!

 

I may have been lucky but used kroil penetrating, let sit 3 days and popped loose with stock wrench that came with bike.

They were very rusty btw.

 

Hold on, is it possible to remove them without removing the headers? Nothing is wrong with the headers, I'd like to leave them on if AT ALL possible.

albert, you said you wriggled it free after that? And THEN removed headers? As in, the exhaust will wriggle free without removing headers?

MetalBob, when I read everything the forum had to say about exhaust, I obviously read your thread as well. Have high regard for aerokroil after reading that thread...

 

Careful here guys, we may be into "apples and oranges" territory...

Depending on which style system it is (full-on "collector box" or siamesed pipes w/crossover) it may be possible to do that, yes.

But in order to do that, you would still need to loosen the head pipes at the head, and the subsequent "wiggling" will beat the bejabbers out of the old pipe-to-head gaskets.

I take it you've found this, then: http://xjbikes.com/Forums/viewtopic/t=29356.html These gaskets should get replaced.

You'd do better to drop the whole system, triage and repair, then refit your viable system with new gaskets. Anything less is asking for a problem down the road.

And by all means, get some Kroil. It works when nothing else does.

Dropping your exhaust system is easy; I had the whole system off my Seca last weekend for collector box rehab and to replace a trashed mounting damper. I had my kid help me re-fit it.

 

From what I understand in the Haynes, the US XJ650s are the only ones without collector boxes, just a straight pipe across. I can confirm that there appears to be no mount points other than the rear brackets underneath the passenger foot pegs and the headers themselves; so, I'm pretty sure I don't have a 'collector box'.

Is it possible to just take the left side of the assembly completely off? I have 2 exhaust gaskets already, so that'd be ideal. Looks to me like I should be able to.

 

Well, for anyone who was wondering, it is indeed possible to remove just one side--at least, it is on the US XJ650 models, which are the only ones (according to Haynes) that have a 'balancer pipe' as opposed to a collector box.

I absolutely doused--drowned--the nuts/studs with Liquid Wrench (I've had good luck and been recommended it in the past, so I had it on hand, and wanted to see if it was worth sticking with), as well as the left side silencer connecting bracket bolts underneath, and the balancer pipe bolt as well.

Yesterday, without penetrating oil, I had tried loosening the bolts connecting the silencer/baffles to the pipes on the right side--they don't look corroded, the look like they're made of corrosion--and snapped both left side ones. They were coming out slowly but popped under the pressure. I was ok with that, I figured they should be replaced anyways, and they're not lodged in the body or anything.

Well today, the equivalent bolts on the left side, after a night of soaking in penetrating oil, all gave and came out. Nothing broke. All the nuts on the studs came off as well, and I didn't even hammer them first. I was very careful and gentle on them, slowly rocking on force, backing off when I felt it was too much, changed positions a couple times, made sure to only apply force level with the nut, not torsionally at all.

I then wiggled the system to the side until the balancer pipe came free... And then wiggled them forward. Voila! Now for the welding. Will be posting before and after pictures.

 

Sounds like you lucked out. Good Job

MN

 

Thanks! It's been welded and put back on. Thing is, there were lots of weak spots, so buddy welded a lot around, kept patching the weak spots that were melting right through. The weld won't tear for sure, but how long the rest of the pipe holds is anyone's guess. Still, as long as it doesn't tear in a hole, I should be able to patch it before a tear spreads--this last time, I wasn't able to identify the noise right away until it had completely torn. Now I'll hear it right away and be able to patch it before it gets worse. Took some before pics, will take some after pics tomorrow in daylight and show you.

SO MUCH QUIETER! It's sounded like a harley the last couple weeks, so much nicer now.