Corroded Exhaust gasket

So... after a fall at the race-track last year... I started to notice this odd noise.. kind of like a vibration... it would come and go... seemed to come from around the right foot-peg hanger... often at idle and a kind of lashing sound around 5000 rpm when giving throttle blips and letting go suddenly...

Every time I went to the mechanic's to get their opinion... what do you know?? It wouldn't make the noise. Typical.

So I gave up and it seemed to go away... then came back... and having read lots of stories about CCT noise, started to think it was that... I even studied all the CCT removal and tensioning threads, took mine off the bike... played around with them, trying different numbers of turns to preload the spring (now know how they work inside and out)... even got a reply from Honda as to how many turns the spring has out of the factory (something many wanted to know)...

Didn't change a thing...

Then while I was squating down like Rossi, at the rear RHS footpeg, blipping the throttle, with the black heatplate off, I realised it was the "gasket" in the header pipe... number 19 according to the diagram... the rear of the two (RHS in the drawing).

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I could see it vibrating.

It's a horrid noise, very annoying and imagine it is making the fueling a little rough.

So I dropped into the Honda Stealers. Never use the Honda stealers mechanics, but a mate has scored a job there as receptionist for the mechanical workshop and figured I could be guaranteed proper treatment...

Anyway, we had a mechanic come into the office and look at the above schematic and I asked whether the entire exhaust system would have to come off in order to change out this number 19 gasket (well, I was going to have both swapped out for good measure)... or if just the two pipes coming out of the rear cylinder bank (not seen in schematic, cut off at the top of the image) could be loosened off... as this would obviously have an impact on time/labour costs... and if the latter was the case, I'd give it a go myself...

He assured me the whole lot had to be "removed" or loosened... and thus I suggested we swap out all the gaskets for good measure as they will surely be rusted and likely to break on removal of the pipes...

Are my assumptions correct?? Is the mechanic right in saying the entire header system has to be loosened if not removed?? Should I really bother swapping all of these "gaskets" out?? Are they called gaskets??

Wondering if anyone can shed an objective point of view so I know how this really works.

There is a how two on PAGE 2 of this thread with photos and full run down.

I had my entire exhaust system off last winter and it wasnt as bad as it appeared to be at first glance. Mine is a 98 though, so no o2 sensors or cats. (I also have flex sockets and long extensions)

You might be able to get those 2 short pipes off without removing the whole thing but it might not be worth the added cussing factor

The gaskets between the engine and pipes will most definitely not be reuseable

Oh i forgot, I also had my rear shock out so that prob made it easy so just dont listen to me   :laughing6-hehe:

[image: View Post]Jackhammer, on 30 May 2011 - 08:34 AM, said:

Oh i forgot, I also had my rear shock out so that prob made it easy so just dont listen to me   :laughing6-hehe:


CHeers...

Anyone else chime in on this for me??

Seb, Bailey, Bueller??

Anyone??

OK, you don't need to remove everything.  Here's what you need to do:

• Loosen the bolts for both front header pipes.  Back them off about 5mm from the plate.
  
• If you have the original O2 sensors still connected, disconnect them so you don't stretch the wires in the next steps
  
• Loosen the top exhaust mounting bolts (either side of the seat).   If you have Staintunes etc, loosen the right rear footpeg mounting bracket so that the Y pipe can come down.  If it is Staintunes, remove the staintune exhausts but leave the Y pipe bolted to the exhaust collector.
  
• Loosen the clamps on the rear headers (behind the right footpeg)
  
• With a rubber mallet, knock the combined collector box, front headers and exhaust pipes assembly down and off the rear header pipes.  Support this weight as it is very heavy!
  
• Note that the front headers are still connected but because you loosened the bolts they are able to "swing" down.
  
• Spend as much time as you like digging out the old gaskets and replacing them.
  
• Installation is a reversal of the above!

Note that I did not loosen the rear header pipes (at the cylinder head) themselves.  That's because that would be a bitch to do and they're a pain to get back on straight.  Also note that the stock exhaust is all one piece which is why you just loosen the top two bolts, leaving it connected to the collector box.  You can remove them if you want - it's not a big deal and it will remove a lot of the weight you're supporting.  They may rest well on the rear wheel though, so that may help take all the weight.

[image: View Post]kaldek, on 06 June 2011 - 04:58 AM, said:

OK, you don't need to remove everything.  Here's what you need to do:

<GET A CUP OF COFFE WHILE I EDIT THE POST EH?>

Hahaha... got cup o' char on the go... how do you take yours??

It would be a real waste to get a mechanic to do this job too.    I've had my exhaust off HEAPS of times (when I fitted Motad headers), and it's a doddle.  You're not even removing any header pipes here either, so all of the hard bits are avoided.

[image: View Post]kaldek, on 06 June 2011 - 05:13 AM, said:

It would be a real waste to get a mechanic to do this job too.    I've had my exhaust off HEAPS of times (when I fitted Motad headers), and it's a doddle.  You're not even removing any header pipes here either, so all of the hard bits are avoided.


Excellent description... you can tell you've been there & done that... my problem is that I'd be doing it "in the street", not in a nice garage and definitely without a bike lift or anything...

Just a quicky... if I'm loosening the front pipes from the motor... I run the risk of the gaskets there being corroded/pitted and breaking on me right? So I may find myself needing to remove all pipes in the end as they go about breaking as I loosen things off...

That's why I figured in the end I'd have to have them all swapped out....

The more I ponder the more I believe I could do it... and the more I worry that the mechanics at the stealers are going to f it up... or take the entire system apart and not be able to get the rear headers back on... as you say they are tricky...

[image: View Post]Auspa�ol, on 06 June 2011 - 02:36 PM, said:

Just a quicky... if I'm loosening the front pipes from the motor... I run the risk of the gaskets there being corroded/pitted and breaking on me right? So I may find myself needing to remove all pipes in the end as they go about breaking as I loosen things off...

Nah - they're copper crush gaskets mate!  They look (originally) like copper O-rings, but when you tighten down the headers they crush flat.  They don't corrode; about all that can go wrong is them not sealing again; but the bike would be no worse than it is today and there's only a chance it will happen.

[image: View Post]Auspañol, on 06 June 2011 - 02:42 PM, said:

The more I ponder the more I believe I could do it... and the more I worry that the mechanics at the stealers are going to f it up... or take the entire system apart and not be able to get the rear headers back on... as you say they are tricky...

Here are the only tools you should need:

• Allen keys (fairing, footpeg bracket, exhaust hangers)
  
• 10mm socket (front header bolts)
  
• 12mm socket (rear header pipe clamps)
  
• 8mm socket (heat shield)

Honestly the hardest part will be cleanly slipping the system back onto the rear header pipes without scratching up the new gaskets in there.   Just in case you do, I recommend a tube of exhaust cement you can buy from auto shops.  It's a paste which dries hard and expands, filling up any gaps and stopping exhaust leaks past the gaskets.

To be super safe, you can buy another main exhaust gasket (18391-ML0-003).  This will cover you in case you need to remove the exhaust pipes from the headers due to them being too heavy, and if the gasket down there gets damaged in the process.

Oh, I forgot to mention there's an additional bolt holding the collector onto the bike.  It's near the sidestand if I recall correctly, but it's #42 on your diagram you posted above.

[image: View Post]kaldek, on 06 June 2011 - 04:16 PM, said:

[image: View Post]Auspañol, on 06 June 2011 - 02:42 PM, said:

The more I ponder the more I believe I could do it... and the more I worry that the mechanics at the stealers are going to f it up... or take the entire system apart and not be able to get the rear headers back on... as you say they are tricky...

Here are the only tools you should need:

• Allen keys (fairing, footpeg bracket, exhaust hangers)
  
• 10mm socket (front header bolts)
  
• 12mm socket (rear header pipe clamps)
  
• 8mm socket (heat shield)

Honestly the hardest part will be cleanly slipping the system back onto the rear header pipes without scratching up the new gaskets in there.   Just in case you do, I recommend a tube of exhaust cement you can buy from auto shops.  It's a paste which dries hard and expands, filling up any gaps and stopping exhaust leaks past the gaskets.

To be super safe, you can buy another main exhaust gasket (18391-ML0-003).  This will cover you in case you need to remove the exhaust pipes from the headers due to them being too heavy, and if the gasket down there gets damaged in the process.

Cheers!! Nothing like straight to the point clear and concise information... someone give this man a beer!! (I'm over here in Spain, otherwise...)

I actually ordered in all the gaskets... they're supercheap. They're at the stealers waiting... Si prolly would detach the "mufflers" (hehehe) from the headers and swap the gaskets out anyway.

Already have the heatplate off from when I pulled the CCTs and was too lazy to put it back on (just kidding, I just didn't have time: work, exams, sheila, etc).

I figure a jack under the cat should do (funny, a jack in Spanish is the same word for cat, the animal... so I'd be putting a cat under the Cat).

Already saw bolt no. 42... gotcha there.

Always wondered what these gaskets were like... but, from the schematic, the ones I really want to change look to be more like sleeves.

Really appreciate this mate!!!

[image: View Post]Auspañol, on 07 June 2011 - 01:53 AM, said:

Always wondered what these gaskets were like... but, from the schematic, the ones I really want to change look to be more like sleeves.

Yeah they're sleeves.  I'm not sure actually why they would even rattle, but it's possible that they're blowing (i.e. not sealing properly).  If the gaskets are in OK shape you can leave 'em in there and just use the exhaust cement all by itself.  It works pretty well.

You should always replace the copper crush gaskets when reinstalling the head pipes - 1. for a good seal and 2. so you don't have to crank down so hard on the studs to get the pipes to seal. nothing like finally getting the exhaust back on, only to have to start all over again after drilling out an exhaust stud!

Jack under the cat is a good idea.

You should have an easier time with yours than I did the last time I installed TBR headers - they use slip-fit joints and they can be a mother!!

[image: View Post]kaldek, on 07 June 2011 - 04:16 AM, said:

[image: View Post]Auspa�ol, on 07 June 2011 - 01:53 AM, said:

Always wondered what these gaskets were like... but, from the schematic, the ones I really want to change look to be more like sleeves.

Yeah they're sleeves.  I'm not sure actually why they would even rattle, but it's possible that they're blowing (i.e. not sealing properly).  If the gaskets are in OK shape you can leave 'em in there and just use the exhaust cement all by itself.  It works pretty well.


Mate of mine (car mechanic but plenty of experience on bikes) said to lay the new gaskets on top of the old ones... but I reckon there would be fitment issues there.

Exhaust goo sounds like a good way to be mthodical and ensure a good seal... but what about future removals??

[image: View Post]SEBSPEED, on 07 June 2011 - 05:40 AM, said:

You should always replace the copper crush gaskets when reinstalling the head pipes - 1. for a good seal and 2. so you don't have to crank down so hard on the studs to get the pipes to seal. nothing like finally getting the exhaust back on, only to have to start all over again after drilling out an exhaust stud!

Jack under the cat is a good idea.

You should have an easier time with yours than I did the last time I installed TBR headers - they use slip-fit joints and they can be a mother!!


Good point. Thanks Seb

[image: View Post]Auspa�ol, on 07 June 2011 - 06:01 AM, said:

Exhaust goo sounds like a good way to be mthodical and ensure a good seal... but what about future removals??

It comes off easy.  It's not a glue as such, just a space filler.

OK so tomorrow morning I pick up the gaskets... ALL of them (just in case... including the main exhaust-to-header gasket and the two rear header to cylinder block gaskets (which I will not even be removing)... but I had them all ordered in when my original idea was to have the stealer's mechanic do it and that's what he recommended... all of them. They're cheap.

Crush washers huh?? Like the typical crushers on the oil-pan draining bolt.

So just one last question before I get in over my head... I was going over the service manual as to how to loosen off the rear mufflers and... do I really have to remove the rear cowl AND fender??? That's going to chew up a load of time... it's like removing the entire rear except the subframe (they call it the seat rail) itself...

Any tips there guys??

[image: View Post]Auspa�ol, on 13 June 2011 - 04:00 PM, said:

So just one last question before I get in over my head... I was going over the service manual as to how to loosen off the rear mufflers and... do I really have to remove the rear cowl AND fender??? That's going to chew up a load of time... it's like removing the entire rear except the subframe (they call it the seat rail) itself...

What?  No way - you just take the seat off and loosen the hanger bolts using an allen key and a spanner to hold the bolt inside the ducktail.   You *may* have to remove the fender if the pipes won't clear it.  

If I recall correctly, I think it's only two bolts.  These two bolts hold the combined plaster fender assembly and metal license plate bracket.

[image: View Post]kaldek, on 13 June 2011 - 05:50 PM, said:

[image: View Post]Auspa�ol, on 13 June 2011 - 04:00 PM, said:

So just one last question before I get in over my head... I was going over the service manual as to how to loosen off the rear mufflers and... do I really have to remove the rear cowl AND fender??? That's going to chew up a load of time... it's like removing the entire rear except the subframe (they call it the seat rail) itself...

What?  No way - you just take the seat off and loosen the hanger bolts using an allen key and a spanner to hold the bolt inside the ducktail.   You *may* have to remove the fender if the pipes won't clear it.  

If I recall correctly, I think it's only two bolts.  These two bolts hold the combined plaster fender assembly and metal license plate bracket.


OK... here's hoping that's the case... I think I recall reading someone's account of swapping original silencers for Leo Vince and they didn't remove more than the plastics... rear footpeghanger I think too... well... here goes...

[image: View Post]Auspa�ol, on 14 June 2011 - 03:44 AM, said:

I think I recall reading someone's account of swapping original silencers for Leo Vince and they didn't remove more than the plastics... rear footpeghanger I think too

Hmm, I didn't think the stock exhaust bolted to the footpeg hanger, but the aftermarket ones certainly do.  Only when you're upgrading would you need to work in that area I think, unless removing it helps make room to swing the original exhaust system out of the way.

[image: View Post]kaldek, on 14 June 2011 - 04:15 AM, said:

[image: View Post]Auspañol, on 14 June 2011 - 03:44 AM, said:

I think I recall reading someone's account of swapping original silencers for Leo Vince and they didn't remove more than the plastics... rear footpeghanger I think too

Hmm, I didn't think the stock exhaust bolted to the footpeg hanger, but the aftermarket ones certainly do.  Only when you're upgrading would you need to work in that area I think, unless removing it helps make room to swing the original exhaust system out of the way.


Exackery... as I have now discovered and assumed prior to getting started, when you want to slip the new gaskets on, just in case I would need sideward play,it's only a case of removing two bolts anyway... I decided the new gaskets would get less scratched up when reassembling if they were placed onto the "male" end of the rear header pipes that come out of the rear cylinder block, the one's you don't have to loosen off for this job unless you're going to replace those crush washers as well (I didn't bother)... and to slip the female end of the Cat. Con. side over the new gaskets when joining the two together and I reckon I was right... there was very little hacking/scratching that took place when using the jack to push the whole exhaust system back up into place... there was one small hitch where this little hook shaped bit that stops the metal clamp/bands from rotating that didn't want to let the forward of the two joints fully engage all the way in... but I had a MFBH at hand and a little tapping a gentle jerking on the forward header pipes... wriggle etc... it finally dropped all the way in...

I had the rear hardbag frame on when starting this job and figured right away it would have to come off as well as the rear plastic fairing/cowl, in order to let the cans drop... I couldn't be bothered removing the bracket for that system that goes in behind the number plate... as you have to remove the number plate light and that's a pain... I figured I'd go as far as I could taking as little as I could off... worked well until I got to the point of wanting to slip the new gaskets on... not enough donward nor sideward play.. so I just loosened off little by little the two bolts underneath the rear tray... the ones that hold the number plate bracket and sundry on. Bingo... finally got to work the cans and Y pipe outward and the whole system downward enough to do the job... the Cat Con and general plumbing end up hitting up against the centrestand so there was only so much play without dropping the rear... I didn't remove those two bolts altogether.. just went about lossening them off until acheiving the required play. That way it's easier to bolt it all back up...

While I was back there I discovered why the number plate light never worked (and why a lot of people have trouble with it)... the wires go through a smallish hole in a rigid plastic molding at a sharp angle and under pressure/tight... so they rub.. one of the two wires was completely severed. There should be a rubber grommet in there Honda!!

So I've almost got the thing back together... am considering NOT changing out the large cat -to-rear exhaust pipe gasket and seeing if it doesn't blow tunes on me... it's hot, I'm doing this outside (no garage) and am fed up with having to work on this bike more than I ride it. I know proper methodical procedure would involve swapping this one out as well. I changed the front crush washer gaskets for new ones.. as suggested by Seb.

Well I'll have a coke (beer later, otherwise I won't get the bike back together today) and think about it...

Photos and run down later...

Cheers Kaldek, I really owe you one here... you just saved me 200�

[image: View Post]Auspañol, on 14 June 2011 - 07:17 AM, said:

So I've almost got the thing back together... am considering NOT changing out the large cat -to-rear exhaust pipe gasket and seeing if it doesn't blow tunes on me.
It shouldn't.  That gasket is pretty tough and can take a bit of abuse.

[image: View Post]Auspañol, on 14 June 2011 - 07:17 AM, said:

Cheers Kaldek, I really owe you one here... you just saved me 200€
Suh-weet!  Glad to know my barely-adequate knowledge helped for once!

[image: View Post]kaldek, on 14 June 2011 - 07:33 AM, said:

[image: View Post]Auspañol, on 14 June 2011 - 07:17 AM, said:

So I've almost got the thing back together... am considering NOT changing out the large cat -to-rear exhaust pipe gasket and seeing if it doesn't blow tunes on me.
It shouldn't.  That gasket is pretty tough and can take a bit of abuse.
Well... my conscientious (or however you spell it, 11years in Spain and my English is waning) and methodical side got the better of me. I went back down after lunch and got stuck into it. You are right, this one, due to it's size, was a much tougher cookie. The other two I was able to ply out almost intact, although they were still soft and pliable, like the new ones. This main and largest one of all was much harder to clean out, it was much more compacted almost soldered into the pipe.. the grey material (don´'t know what that is, in the past I guess it would have been asbestos maybe but in the modern day that stuff is banned right?), was very flakey and brittle, but the metal netting was tough as a Tonka toy... I cleaned it up good and brushed off with a copper wire brush... and up ended the pipes to get all the gritty bits out before reassembling.

I went so far as to solder up the severed cable and put 3 layers of heat shrinking isolation material on.. and found a rubber that will do as a grommet... Honda should employ me.   :laughing6-hehe:

[image: View Post]kaldek, on 14 June 2011 - 07:33 AM, said:

[image: View Post]Auspañol, on 14 June 2011 - 07:17 AM, said:

Cheers Kaldek, I really owe you one here... you just saved me 200�
Suh-weet!  Glad to know my barely-adequate knowledge helped for once!


R u kidding?? Your hands-on knowledge is a big help and the dedication to posting up your experience in a range of areas shows your willingness to help.
It's the kind of layman's knowledge that sits well with me. If someone comes at me with theoretical prowess they'll run circle's around me... but when it comes down to it, it's getting your hands greasy and busting a knuckle that counts, and then spreading the word, helping out someone you don't even know. That's VFRD mate!!

Tomorrow the real test as to whether my new suntanned arms and legs were worth the effort.

Talk about decent timing- my rear downpipe gaskets started to blow yesterday, was wondering how much of an arse it was going to be to change it, doesn't sound too bad, cheers Kaldek!

Just got to find some gaskets now....

[image: View Post]cgrieves, on 15 June 2011 - 11:11 AM, said:

Talk about decent timing- my rear downpipe gaskets started to blow yesterday, was wondering how much of an arse it was going to be to change it, doesn't sound too bad, cheers Kaldek!

Just got to find some gaskets now....

I bought mine at the Honda dealer's because intially I was going to trust them to do the job... I repented and decided to do it myself (I don't trust them and the money can be used on a weekend away with my girl at the Canary Islands)... �which would you choose?

You will get them cheaper on-line somewhere like Ron Ayers...

Don't bother with 4 engine port-to-header crush ring gaskets... you won't be touching the rear ones for this job like I thought I would... and I would have, but I don't have a bike elevator tray thingy and access to those two is a PITA... If you have a decent garage and tools and space, you can get this done in a couple of hours... I don't so I took longer.. but having done it once, if I ever had to do it again, it would take half the time.

Photos and a how-to type write up to come if you can wait a couple of days...

[image: View Post]Jackhammer, on 30 May 2011 - 08:28 AM, said:

I had my entire exhaust system off last winter and it wasnt as bad as it appeared to be at first glance. Mine is a 98 though, so no o2 sensors or cats. (I also have flex sockets and long extensions)

You might be able to get those 2 short pipes off without removing the whole thing but it might not be worth the added cussing factor

The gaskets between the engine and pipes will most definitely not be reuseable


I should also extend my thanks to you Jackhammer... as at least you armed me with the confidence that it was DIYable!!

BTW... bike sounds wicked again... the horrid noise it was making had me so shameful I even skipped a meet and was using the gf's cage more often... now it sounds like a Honda V4 once more... and I am now able to tell if there is CCT noise or not... and guess what... of course there is   :pissed:    :pissed:

Anyone know the sizes of the two rear header gaskets? I mean the ones halfway down the downpipes, not the cylinder head gaskets. Or even a part number?

I've found plenty of places selling them in 37.5mm or 41mm sizes, but I can't find any info about which are for FI models, and which are for VTECs....

[image: View Post]cgrieves, on 16 June 2011 - 07:02 AM, said:

Anyone know the sizes of the two rear header gaskets? I mean the ones halfway down the downpipes, not the cylinder head gaskets. Or even a part number?

I've found plenty of places selling them in 37.5mm or 41mm sizes, but I can't find any info about which are for FI models, and which are for VTECs....

FI = 5th gen I assume??

Well mine's a VTEC and I took a couple of photos for posterity... but I didn't measure the height   :happy:

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32mm interior and 36mm exterior diameters. Height?? Maybe 25mm but I didn't measure it... I was taking photos of the measurements and then said to myself... Bahh.. no-one's gunna want that info...   :blush:

Yeah sorry Fi=5th Gen! Mine's a VTEC.

Cheers for the measurements, I found somewhere that sells a kit for VTECs, I'll double check they're the same as yours before I pull everything apart.

Many thanks!

[image: View Post]cgrieves, on 16 June 2011 - 11:43 AM, said:

Yeah sorry Fi=5th Gen! Mine's a VTEC.

Cheers for the measurements, I found somewhere that sells a kit for VTECs, I'll double check they're the same as yours before I pull everything apart.

Many thanks!

No worries. Over here in Spain we call the 5th gens FI as well (or RC46) and the 6ths VTECs (or RC46II)... and the 4ths RC36II and the 3rds RC36.

Procedure for removal of headers/exhaust pipes 6th gen VFR800 (VTEC).

Remove Seat. No photo needed right?

Remove Hardbag Racks if applicable.

Remove LHS, RHS and Front Lower Cowl (the latter is black, unpainted).

Remove Rear Cowl: In order to do so, remove electrical connections from the rear light/indicator housings, 4 in all. Disconnect the white Number Plate Light connector also. While you’re there, run this wire out through the holes perforated in the rigid plastic.

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BTW, you may well find this cable severed from rubbing on said plastic. If so, fix it!!

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Two holes for this step, one up near light connectors on the RHS rearmost end of things (as shown above) and the other in the fender/mudguard. Removing it makes the next step possible.

Remove the rear Number Plate Housing/Fender/Mudguard unit (6 bolts, 4 accessed from above and 2 from below).

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Remove RHS Rider’s Footpeg Hanger and Heat Shield in one piece and hang out of the way of the header clamp pinch bolts.

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I had the heatshield removed from a previous job on the rear CCT.

Disconnect the O2 sensor connectors (near lower edge of stator cover, LHS of the bike). They should be in a rubber hoody.

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Now you can get stuck into it.

I used a small $12 trolley-style jack from Kmart to prop up possible weight. I originally placed it under the two forward headers where they start to separate�

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...but later found this did not allow me to drop the exhaust system enough to swap the seals/gaskets out.  Place it where the centrestand stop is, if you rear wheel allows you to look for the highest point you can stick the jack under, to get maximum drop when lowering the whole system.

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I ended up removing the jack altogether once I realized the thing would rest on the number plate/fender/mudguard assembly (which I hadn’t removed, just loosened until I got enough play in the pipes) the cans were resting on the wings of the plastic number plate hanger (I had removed the number plate itself).

I'm pretty sure the cans would rest on the rear wheel perfectly, so that is what I recommend above. I didn’t find it all so heavy as I had been warned� although did make use of the jack stuck up close to the centrestand stop, to lift the whole thing back up when reassembling.

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If you aren't swapping out the large headers-to-exhaust up-pipe gasket, then just loosen off like I did. It was later, when I decided to swap this main gasket out as well, that I pulled the rear mudguard assembly off completely.

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I removed the RHS passenger footpeg hanger to get complete sideways freeplay (highly recommended to remove this part, there are only two bolts so� you decide.)

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I used a WD40-equivalent spray on all exhaust clamp pinch bolts as they are rusted to buggery and at least one didn’t want to budge� liberal “3 in 1” (typical Spanish brand of WD40-like stuff) and some tapping with a MFBH and long rod (to get in there) and lots of wrist intelligence so as not to break the clamps� I thought I was going to have to get out the angle grinder on one of them but it finally decided to cooperate.

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You can see how it ended up. Bent even� and the threads were fugged� I got out the tap n die set�

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I removed these bolts and cleaned them up with a copper wire brush (don’t want to ruin the threads, just clean them up) and more WD40.

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Don't loosen the large ones for the main headers-to-exhaust up-pipe gasket yet. Just the two S-bend ones (as I call them).

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You can see a metal radiator hose clamp I used as a temporary measure to keep the blown seal from making that horrid noise.

Remove the main exhaust system hanger bolt. It's number 42 on the spreadsheet. It's the most difficult one to access. Hold the RHS nut still with a spanner and work the LHS with a ratchet on a short extender, the smallest size ratchet and a short maybe 2.5 cm long extension. It will fit.

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Here you can see the hole where the bolt goes all the way in there� the centrestand gets in the way a bit. Warning: the following images contain chain grease spooge. You have been warned.

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I tried using an elbow extender at first but the force required to loosen the bolt just split the thing in two.

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Remove the front pipes from the engine block. Remove the crush washers. You do have new ones don’t you?? These are double ended bolts�  3 of mine acted like nuts and one came out as a bolt.

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I figured best to have the system supported on a jack right?? Better to let it down gently I guess.

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Don’t do the large main headers-to-exhaust up-pipe  gasket first, don’t even loosen its pinch bolts as it states in the manual� as it may suffer later when you’re wrestling with the other two S-bend gaskets, and if you're not intending to swap it out or don't have the replacement gasket, the less it suffers the better.

Remove the two bolts which hold the cans to the tail.

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You should now be able to separate the two S-bend joints. Wriggle things and use gentle persuasion with a MFBH if needed, while lowering the jack.

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Clean out the old gaskets. Try not to let too much fall into the pipes unless you’re going to pull the whole system as you can’t tip these ones upside down to get the crap out. Maybe a strong vacuum cleaner held in place while you remove the old gaskets would be the thing.

Remember, you can’t blow them out by starting up the bike when it’s all reassembled as the flow goes from there to the Cat� which is essentially a filter, so you’ll just be plugging up the works.

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I used a small flathead screwdriver. In retrospect I guess you could place a trap inside the pipe before starting to clean out the old gaskets. Make a disc with a layer of tape, sticky side up that fits snuggly into the pipes� with a string to be able to retrieve it� just an idea.

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Once again I used the copper wire brush to clean up a bit.

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A mechanic friend of mine said to place the new ones on top of the old ones and not bother removing them� This did not seem physically possible once I had the whole thing apart. I placed the new gaskets onto the male of the two ends, not into the female from where I had just removed the old ones. It seemed clear to me they would suffer less scratching on reassembly this way. It’s your time and money if you prefer to do it another way. I may be wrong.

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There is an order to removing and reassembling the exhaust system, and reassembly is not necessarily the reverse of disassembly. You must follow this order if you don’t want to feel like a knob and suffer from unnecessary headaches or revert to drinking to see if you can’t get inspired.

These things are definitely NOT reusable. Get your spares in hand BEFORE attempting removal of exhaust system.

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I got a new radiator cap� after 90,000 km I figured I would do some preventative mechanicking.

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Hmmm interesting crack.

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Got some weird gunk on the up-pipe� have no idea what it is� Kling-on??

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The copper crush gaskets are not held into place by anything on any side, so, I bolted up the pipes to the engine block, leaving just enough space to work them in, before continuing to bolt up and keeping an eye on them to make sure they were well centered. I used a thin flathead screwdriver to prod them into place as they tended to want to move off to one side.

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When reassembling, remember you don’t torque anything down until all the bolts are in� this allows for freeplay and thus easier alignment. Remember never to torque one bolt up completely while the other is only a few threads in� alternate from one to the other (especially on the front header to engine block ones).

Order for reassembly (first just introduce the bolts, don't tighten):

Front headers

Main Exhaust System Mount (the hard to get to one that bolts the cat to the motor down near the centrestand).  Bolt # 42 remember?

Make sure the S-pipe clamps are on the flanges of the S-pipes.. I didn’t remove them so they were obviously still there.

Mufflers (Cans to you Ameri-cans).

Now TORQUE ‘EM ALL UP. Remember to alternate every couple of turns on the front header-to-engine block special bolts.

Front

S-pipes

Main Mount

Muffler

OK� this last one, not yet, IF you are going to swap out the Cat-to-up-pipe gasket.. you know, the humungous one. It can take a little worming to get the up-pipe+cans assembly to come free off the Cat Converter but you just work it side to side while pulling away. The gasket was well soldered on. Up end the thing to let all the chunks out before you assemble it back on.

All clean:

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I had professional supervision.

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Remember this wire? Soldered this worn-through wire (number plate light)�for the lack of a rubber grommet Honda� shame on you.

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Rear number plate hanger made a good soldering iron accessory. Why I say rear I don’t know, there is no forward one!!

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Triple heatshrunk it so it won’t rub through in several centuries.

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I reckon that's it. Time for a brew...

Mate do they salt the roads there or something, coz your pipes are fuggin rusty!  I pulled mine off at 128,000KM and they looked great!  Of course they're in the shed now, neglected since they were replaced by a set of Motads.

'Course, she's been garaged all her life....

[image: View Post]cgrieves, on 16 June 2011 - 07:02 AM, said:

Anyone know the sizes of the two rear header gaskets? I mean the ones halfway down the downpipes, not the cylinder head gaskets. Or even a part number?

I've found plenty of places selling them in 37.5mm or 41mm sizes, but I can't find any info about which are for FI models, and which are for VTECs....

Honda part code is 18391-ML8-000.  You need two of them; the price is $10.95 each according to Honda Parts House.

[image: View Post]kaldek, on 17 June 2011 - 07:49 AM, said:

Mate do they salt the roads there or something, coz your pipes are fuggin rusty!  I pulled mine off at 128,000KM and they looked great!  Of course they're in the shed now, neglected since they were replaced by a set of Motads.

'Course, she's been garaged all her life....

No man, no salt where I live... it's hotter than where you live... think of Mount Isa...

Basically this bike lived outdoors without a garage for several years... with a decent cover but nonetheless outside... and I have done lots of riding in the rain... and live reasonably close to the coast... and the water's very hard over here...

You're right, they are fugly!!! Wish I had the cash for some nice shiny new Stainless ones... if I had time I would have completely removed them from the bike and got stuck in with grinding and sanding  and then paint them... but, they'd just rust out again... and I use the bike almost everyday.

For the copper cylinder to pipe gaskets (crush washers) on my 5th gen, I "stuck" them to the engine with some grease, then bolted up the pipes.

Brilliant guide, thanks Auspanol!

[image: View Post]Veefer800Canuck, on 17 June 2011 - 10:31 AM, said:

For the copper cylinder to pipe gaskets (crush washers) on my 5th gen, I "stuck" them to the engine with some grease, then bolted up the pipes.

Yeah I did think of that... but didn't want the stink... it wasn't a difficult thing to overcome... in other cases I have used a little oil or grease for applications in hard to get places...   :fing02:

[image: View Post]cgrieves, on 17 June 2011 - 10:49 AM, said:

Brilliant guide, thanks Auspanol!


Hope it makes life easier for ya!!

[image: View Post]Veefer800Canuck, on 17 June 2011 - 10:31 AM, said:

For the copper cylinder to pipe gaskets (crush washers) on my 5th gen, I "stuck" them to the engine with some grease, then bolted up the pipes.

Hey that's my trick too!  Did stink for a minute or so, but saved me a bunch o' hassle.

The guide worked a treat- replaced my rear header gasket on Sunday. Found the the clamp on the rearward pipe had disappeared, so the gasket had slowly blown itself out over time, there was virtually nothing left. I used a couple of hose clamps for the moment until I can get something more permanent. The other gasket was fine, plenty of meat on it, so I left it.

Also my collector box mount had sheared off, just as well as the bolt was just a bit lump of orange crud. The whole collector was surprisingly light so I think the rest of the system should support it OK.

I also reattached my O2 sensors and zeroed out my PC3 map under 5K as it's never really run right, and my fuel economy is crap. I've now got an FI light, but confusingly only when the bike is upright or leaning right- on the sidestand it's intermittent. Wiring I suspect, or maybe having had the sensors disconnected (and not heated) has killed one or both.

Bike sounds a bit less MotoGp now, but a lot better for it. Much less vibration too.

[image: View Post]cgrieves, on 27 June 2011 - 03:37 PM, said:

The guide worked a treat- replaced my rear header gasket on Sunday. Found the the clamp on the rearward pipe had disappeared, so the gasket had slowly blown itself out over time, there was virtually nothing left. I used a couple of hose clamps for the moment until I can get something more permanent. The other gasket was fine, plenty of meat on it, so I left it.

Also my collector box mount had sheared off, just as well as the bolt was just a bit lump of orange crud. The whole collector was surprisingly light so I think the rest of the system should support it OK.

I also reattached my O2 sensors and zeroed out my PC3 map under 5K as it's never really run right, and my fuel economy is crap. I've now got an FI light, but confusingly only when the bike is upright or leaning right- on the sidestand it's intermittent. Wiring I suspect, or maybe having had the sensors disconnected (and not heated) has killed one or both.

Bike sounds a bit less MotoGp now, but a lot better for it. Much less vibration too.

You really should get a bolt into the Cat mount... the system will move and vibrate more without it and that means shorter lifespan for your gaskets... don't know about leaving an old gasket in there instead of pulling it and shoving a new one in... unless you're sure it didn't get scratched up on reassembly.

At least you got rid of the unwanted nose factor...  glad to be of help.