Exhaust leak

[Boris]

The exhaust of my 05 vara is blowing at the clamp where the rear cylinder header pipe meets the collector box and I understand that this is not altogether uncommon and both the clamp and the carbon graphite gasket/olive need changing.

My question is what is the best way to do this. Is it easier to remove the header pipe to the rear pot or do I need to drop the collector box? If I need to drop the collector box will I need to replace the other gaskets at the same time?

Anyone done this before and can offer some advise?

[StumpyFingers]

I would buy the complete set of gaskets and remove the exhaust and replace the lot, if one has gone then the others may not be far behind and the time it takes to do one is not much different from the lot.

[clutchspring]

Hi Boris,
I did the same job on my o4 a few months a go,

I read all the posts and most said you had to drop the collecter box , but I did it buy just removing the rear down pipe, I as suprised at how easy it was To give me more room i removed my hugger & back wheel , the down pipe came out easy, the two bolts in the barrel came out as studs with the nuts still attatched,You will need a new port gasget and new sealing ring gasget, I allso got a new clamp from my local bike shop full stainless steel £3.70 and alot better than honda clamp about £20 plus the bolt, the only time consuming bit is opening out the collecter pipe to take the new sealing ring, I used sockets starting of with one that fits in the pipe then rocking it about until you can get the next size socket in ,keep doing this until the sealing ring drops in I think it was a round 32mm, take your time as the new seal is quite soft, good have fun, Ian.

[Boris]

Thanks to all who posted (and J who PMed me) for the advice. I picked up the bits this morning and set about it this afternoon. I had thought about removing the header pipe only but the Honda main dealer assured me it couldn't be done that way so I had already got all the bits and started by the time clutchspring posted to say it could be done after all.

The time consuming bit was removing the bodywork, centrestand and the pannier frames before I could get to the clamps, two of which had seized solid. The can I managed to remove by just twisting it off and the other seized one was the one that was leaking and as the gasket had all but gone it came off without having to remove the clamp. Once I had the pipes off I had to cut the clamps off as the captive nuts had come adrift.

The actual gasket, which should be like a length of carbon pipe about 40mm long had disentegrated and all that was left was about three 5p sized peices.

New gasket at the front pot and it all went back together without too much problem. All in all it took about 4-5 hours but I was on my own and a lot of jobs would have been much easier with another pair of hands. I also repainted the centrestand while it was off the bike.

Thanks again all.

[Snaphappy]

Sorry to see this far too late

I done mine last week

the night before I sprayed the clamps and header bolts with WD40
They came apart with ease but I was worried, the gasket had completely disintegrated and the pipes came apart easily, I managed to get the header pipe out easily enough and replaced it facing the rear and used it as a lever to open up the downpipe sufficiently to slip the new gasket in, replacing the pipe was a pain it was almost like I needed another mm but with a bit of strain it when back in.
I didn't remove any thing else just the downpipe an octopus could have done it in 20 mins it took me 90 mins

sorry its too late for you Boris but it might help someone

[StumpyFingers]

I have not had to replace the gaskets, on this bike but in the past on other bikes I have found it quicker in the long run to drop the whole exhaust out, then completely refit it with new gaskets.

[Freerangestormer]

+1 for doing the lot in one go.

I didn't do it myself, no facilities here, even though I'm an engineer who likes to get his fingers dirty. My mechanic & I looked at the job and decided the whole lot had better come off.

He did it himself in the end and was glad he took the lot off and replaced all the joints.

[Dee Duble Yuh]

Ordinarily you'd expect all the gaskets to deteriorate at a similar pace, so replacing the lot at the same time would make sense. However, there's something about the faulty gasket in question that means it disintegrates long before the others. Since clutchspring's method disturbs far fewere components it's the approach I'd attempt next time... hopefully that won't be for a while though!

[Freerangestormer]

As my Mech said

glad he took the lot off and replaced all the joints

the others were about to fall apart, I may have pics, let me look.

[Boris]

Had I just removed the downpipe I'm not sure how I would have managed to cut the clamp off. I did give the clamp a good wire brush and a soaking in WD40 the day before but the captive nut still separated when I tried to loosen it. Fortunately as the gasket had gone the pipe separated easily without loosening the clamp and I could cut it off when I had the collector box on the bench.

The two gaskets on the link pipes to the cans were fine so I left them unchanged. I will get a third stainless clamp and replace the only Honda one left (I bought 2 stainless ones just in case) as I don't have much faith in the Honda ones any more.

If I were to do it again I would just remove the header pipe IF I could undo the clamp before I started. Otherwise go for the collector box off.