[johnmac]

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My '85 1200A has had an exaust leak since I've owned it. It seems to be comming from the head pipe area.
I am ready to fix the problem but I have a few questions.
Is the head pipes double walled? It sounds like the inner wall is rotting out, and is now leaking thru the outer wall.
Is the seal between the head pipes and mufflers reusable, or should I have new ones on hand?
And last, I read on another post one time that the nuts at the heads would probably break off, and vise grips can be used to remove the broken stud. If the nut is frozen to the stud, won't the stud unscrew like a bolt? I don't want to have a stud break off right at the head, that would be a real pain.
Any advise would be great!

Thanks,
John

 

[exavid]

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johnmac wrote:

My '85 1200A has had an exaust leak since I've owned it. It seems to be comming from the head pipe area.
I am ready to fix the problem but I have a few questions.
Is the head pipes double walled? It sounds like the inner wall is rotting out, and is now leaking thru the outer wall.
Is the seal between the head pipes and mufflers reusable, or should I have new ones on hand?
And last, I read on another post one time that the nuts at the heads would probably break off, and vise grips can be used to remove the broken stud. If the nut is frozen to the stud, won't the stud unscrew like a bolt? I don't want to have a stud break off right at the head, that would be a real pain.
Any advise would be great!

Thanks,
John

I'm not sure but do think the 1200 headers were double walled. Probably should have new seals, the old ones tend to break up. Yes the studs to have a propensity to break. If they do you might try the method mentioned on a forum topic (sorry can't remember who posted it) but heat the stud with a torch and then touch the bottom of it with some solid paraffin. As the stud cools it should draw the paraffin into the threads and help loosen them. Go slowly on them.

 

[Ken Tripp]

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I don't believe they are double walled but I'm not a expert (yet). The gasket between the header and muffler is reusable - or at least I've removed and reinstalled without getting a new gasket. I will add that when I originally tore mine apart it didn't even have the gaskets. I bought new ones. It's kind of like a plastic resin cylindrical gasket. There are also copper crush ring gaskets between head and header. These probably should be replaced. Might even be the cause of your leak. Once you get the headers off might want to check for rusted holes, etc.

I've been pretty lucky in getting the studs out. Before you go wrenching on them, I'd spray something on them to help free them up. Then double nut them and back them out slowly. If they are stubborn, maybe using a bit of heat on them to help them out.

If you have the crash bars over the valve covers, it's kind of a contortionist trick getting everything lined up when putting them back on. Just take your time and do it right the first time. Might also want to check the shifter seal while your down there. Easy to replace if you have all the other stuff off.

Ken

 

[englishted]

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John, the seals between the pipes and mufflers can be reused if they are still in one piece. They do last a long time.

 

[rcmatt007]

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sometimes the studs will come out like a bolt and so are reusable. When I had my pipes off, about half unscrewed, the other half unbolted and none broke.

 

[Mr. Fix it]

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If the header is the older style where the 2 header pipes are collected immediately into the collector box then yes you could consider them to be double walled.

(I have a header sitting on the floor right now that needs to be sealed up with some brazing rod so it can be re-used again because the outer wall has burned through where the first pipe goes into the collector box).

If they collect near the back of the header pipe then it is not double walled.



The torch trick will work as will a propane torch may as well do the trick because it is a gentler heat . You won't get the nuts to turn a rosey orange colour but if you use some WD -40 to cool the nut after heating, then it may break loose for you as well simply by means of the quenching process. Heating and quick cooling will break down any rust that has accumulated over time between the nut and stud.

It all depends on the condition of the studs. If they look pretty good to start with then you should be ok. If they look thinner and normal then easy does it with the heat.

They shouldn't be too tight to begin with..

Re-assembly you should use some anit-ceasing compound for future removal..



All the best!