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Discussion Starter · #1 ·
The last and only other time I dropped my engine I made a moderate attempt to seperate my exhaust pipes from the H-box with no luck and ended up taking them away and then re-installing them (the two pipes and the box) as one piece since I had more pressing issues to deal with.



Since then, however, I've procured a much more attractive set of pipes and would love to swap them out with the much grungier ones that refused to cooperate the first time around.



Has anyone ever fought this battle and won?? I'm dealing with an '81 Custom with 75K on the odometer. Heat?? Solvents? I fear getting too heavy handed and trashing the box and/or the pipes that are now on the bike and perfectly funcional.



Thanks, as always, for any thoughts on the matter.....;gweric
 

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I´ve only had limited success with penetrating fluids, although they may not hurt, either.



As long as the old mufflers (and H-box) are in reasonable nick I always end up doing it this way:



Loosen the clamps and brackets - quite obvious, eh?



Try to wiggle the mufflers up and down, as well as sideways. They don´t want to co-operate, but if you try just a little bit more - just as much as needed to widen the slotted H-box opening a little - they should. No need to be brutal, only determined.



Go on with the wiggling and you´ll feel when things start to happen. Maybe also some mallet blows on the bracket behind the muffler rearwards will help. More wiggling, and soon enough you should (hopefully) have the muffler separated without damages - now if it (and the H-box) was reasonably sound from the beginning.



At least that´s the way I´ve always done it. Once I lost a couple of mufflers but they truly weren´t worth saving, anyway. Totally rotted, where they connected to the H-box.



Sture
 

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Last time I took one apart it was just a matter of a lot of time and work as described above so I feel your pain. I also found that spreading the tangs out on the H-box with a screwdriver + hammer helped but it ends up destroying the hard to find gaskets. Plenty of ways to replace those though, some have used that thick aluminum foil (or foil tape) + hi-temp Permatex, others have just used muffler tape which I'd avoid because it tends to seal up permanently.
 

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What works best for me is to spread the tangs slightly with a screwdriver. Then apply Kroil (or maybe an ATF/acetone mix) to the joint and let it sit for a day to work in. Rock the pipe side-to-side and twist back and forth while pulling apart.



For tough cases the whole process may need to be repeated.



The gaskets usually get destroyed in the process but they are still available from Honda, although they are expensive.
 

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try using PB Blaster. Squirt it in and let it set for awhile, then squirt some more , let set, squirt some more. Every cpl hrs. about 4 or 5 times and then let set for a cpl days. Works for me.
 

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Discussion Starter · #6 ·
Thanks to all who had a say in the matter...I'm gonna give it a go sometime this week and I'll let you know how it goes....have to find my sledge hammer first...just kidding...thanks, gweric
 

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Well if it is solid then there's a good chance that they can be separated. If they aren't then you're looking at a mess. I have destroyed a few.
 

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I've found CX ex boxes or at least the two i've done to be fairly easy to get off the bike and take apart . I block them up with soft plywood, use hardwood rods driven by a three lb maul... and somewhat carefully beat ( the crap out of ) them apart. Typical, as things like this start to give a little in one place, I keep shifting point of impact one side to the other. sooner or later
they will fall apart as if it was easy...






PS. I had one on a j yard bike that I really smacked with a couple 2x4s expecting to damage it. I just wanted to fill the pipes and box with water to measure their internal volume(s) (guess why Reg
) Surprisingly, all beating it good it seemed to do was loosen a load of internal rust leaving the header and box AOK.. when they fell apart.





O.T> P.S. Does Anyone know the internal volume of a stock 82cx500 airbox. I need a aprox figure from the butterflys through the box it'self to the cold air intake boot edge.
 

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You're talking about the pipe from the motor the the H-box, not the mufflers right? I don't have anything else to offer other than good luck. I'm out of town right now but will be back in S.F. Friday. If you haven't attempted it by Friday, I'll come over and stare at it with you. Also, I have a torch. Sometimes heat can do wonders to things that are stuck.
 

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I too had difficulty separating one header (thought not the other!) from the H-box. My solution was plenty of penetrating oil, time to soak, and a rubber mallet. Crude but effective.



Good luck to the effort.



STAN
 
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