joint sealer - exhaust header to muffler - good idea, bad idea?

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No definitely not
Some people leave the clamps just nipped up I have heard to allow for movement so a sealent that set rigid could be a problem? Others may know better
 
If you need to pull your mufflers off at anytime, I say no, use good clamps and you should have no problems.

Ashley
 
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OK - looks like the consensus is no on the sealant. I have a couple DRC, 360°band clamps that i'll be using, so I should be good to go. thanks for the replies.
 
NO ...bad Idea for sealer
also especially on the balance pipe couplers on 850's. I antiseize one end of each balance pipe coupler and leave the clamp loose and tighten only the other end of the coupler tubes.
Why?
heard of cracking header pipes? a hot aluminum head expands more than the steel pipes and then, if clamped, works the welded joints during the thermal cycle.
Yes only a theory but since 95 ( my first 850) my oem pipes have never cracked! So I will continue this method until I find it does not work :)
 
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I have a set of mufflers that are so loose on my pipes that they would rattle even when nipped up with good clamps. It drove me nuts, so I wrapped a single layer of fiberglass tape around the end of the pipe and stuck the ends down with some high heat RTV. Then carefully slide the muffler on. It stopped the rattle, they can still flex and come apart. The tape serves to collect carbon at a good rate for sealing.
 
I've heard of and since used silicone sealant othe header to silencer connections on other bikes. Easy to separate when needed, handles small air leaks etc. Might use some on next time on commando pipe joins.
 
rvich said:
I have a set of mufflers that are so loose on my pipes that they would rattle even when nipped up with good clamps. It drove me nuts, so I wrapped a single layer of fiberglass tape around the end of the pipe and stuck the ends down with some high heat RTV. Then carefully slide the muffler on. It stopped the rattle, they can still flex and come apart. The tape serves to collect carbon at a good rate for sealing.
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That's why they invented reducers for, I have used reducers before without any problems, on my Commando/Featherbed I can remove my header and muffler off in one piece just undo the header rose and one muffler mount bolt, take less than 2 minutes at the most, my pipes don't need any flex.

Ashley
 
dynodave said:
NO ...bad Idea for sealer
also especially on the balance pipe couplers on 850's. I antiseize one end of each balance pipe coupler and leave the clamp loose and tighten only the other end of the coupler tubes.
Why?
heard of cracking header pipes? a hot aluminum head expands more than the steel pipes and then, if clamped, works the welded joints during the thermal cycle.
Yes only a theory but since 95 ( my first 850) my oem pipes have never cracked! So I will continue this method until I find it does not work :)
Click to expand...
This is good advice for the crossover pipe thermal expansion/contractions cracking dilemma. Recently mine cracked on the left side and opened up. I took it to a man in welding school and he said this is not a weld but a braze. He put together a jig brace for it and re-brazed it up for $50.
 
Torontonian said:
This is good advice for the crossover pipe thermal expansion/contractions cracking dilemma. Recently mine cracked on the left side and opened up. I took it to a man in welding school and he said this is not a weld but a braze. He put together a jig brace for it and re-brazed it up for $50.
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850 roadster or interstate (colleted spigot) or MKIII roadster (flare)?
The one pipe I pulled down to look at (850/interstate) has rust across the weld therefore not brazed on this one. I have a little over 2 dozen sets of old pipes and a few new ones. Most are OEM take offs and I had not thought that any were brazed except some very sloppy and obvious repair attempts. You never know...
Thanks for looking
 
dynodave said:
850 roadster or interstate (colleted spigot) or MKIII roadster (flare)?
The one pipe I pulled down to look at (850/interstate) has rust across the weld therefore not brazed on this one. I have a little over 2 dozen sets of old pipes and a few new ones. Most are OEM take offs and I had not thought that any were brazed except some very sloppy and obvious repair attempts. You never know...
Thanks for looking
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1976 colleted spigot would likely apply. One of the last ones. A braze not a weld .
 
Torontonian said:
1976 colleted spigot would likely apply. One of the last ones. A braze not a weld .
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???
Colleted spigot is 73/74 850 and are totally different pipe and hardware in the port and not really suitable for 75 MKIII.
76 & 77 to me are just the debtor's late liquidation of 75's.
IIRC there was a thread detailing and identifying the pipe types quite well, however manufacturing technique with weld or braze was not discovered or discussed. I'll try and find the link and also look at more pipe joint materials.
DJC
 
so with all this talk about brazing, welding, cracked pipes, etc., i'm assuming any cracking is due to the crossover balance tube. question, what's the best method for assembly that will compensate for any thermal expansion? right now, my center tube joints seem to fit perfectly between the header pipes, and the couplers centered to those joints. i torqued the finned exhaust nuts first, then followed up by securing the coupler bolts. during assembly, i tried to keep things aligned without any noticeable binding. i used stainless hardware on the couplers. the exhaust feels very solid, with no give, so if thermal expansion is a problem, i may be in trouble here. is there a method to secure these pipes, allowing for thermal expansion, without having exhaust leaks? again, the whole problem seems to be centered around the balance tube/crossover pipe.
 
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