Exhaust header clamp confusion please help

[Nibsy]

Doesn't Marving have full exhausts? What about Exactrep? Or is that who sold you this bike in the 1st place?

I think Marving do a system but you have to use your existing rear headers. I’d ideally like a full system with a better clamping arrangement. And yes, you are correct, I did buy it from Exactrep.

 

[Fire-medic]

Well, some shim-stock in different thicknesses may allow a better grip, if placed under the pieces, between them and the header pipes. Is it the fronts in-particular which have given you issues?

 

[user 16790]

have you contacted exactrep to see if they know what the problem is

 

[Nibsy]

Well, some shim-stock in different thicknesses may allow a better grip, if placed under the pieces, between them and the header pipes. Is it the fronts in-particular which have given you issues?

No it’s the rears.

 

[02GF74]

. I think the bike was cobbled together from loads of different parts. Think I got shafted to be honest and regret buying it now.

There are two approaches: work on it to get it fixed, which may mean paying somebody else or sell it.

I';ve watched the video but don't understand what connects on the other end - is there a similar metal ring on the adjoining piece so the clamp goes over both?

The clamp must squeeze some other part that deforms to take up space, seal the exhaust and hold it in place - that presumably is the copper piece since it is the softest metal.

I see the metal ring has a very thin section so the may be eaisly deformed - have you tried putting the copper ring over the thin section, as shown by the orange arrow?

As mentioned above, isn't there a similar steel ring that goes over the next section of exhaust the the clamp goes over? If so then maybe there should be two copper ring that when fitted, the two steel rings are slightly apart from each other and when clamped, are brought together so the copper rings deform?

 

[Stephan]

I fitted a Black Widow stainless steel system to my generation 1 1996 bike and it fitted and worked extremely well, but it does use the standard rear headers because they are stainless anyway so does not solve that problem for you.

 

[Nibsy]

have you contacted exactrep to see if they know what the problem is

I have contacted them over other issues (the bike has lots of them) - they were less than helpful. I suspect, going by some of the posts i’ve read, that they have fitted cheap aftermarket front headers, which seem about an inch too short…..as for the rears, it’s the stock Yamaha set-up and other members on here have had the same issue.

 

[Screwloose]

I have contacted them over other issues (the bike has lots of them) - they were less than helpful. I suspect, going by some of the posts i’ve read, that they have fitted cheap aftermarket front headers, which seem about an inch too short…..as for the rears, it’s the stock Yamaha set-up and other members on here have had the same issue.

Hi Nibsy

I’ve had a look at mine (originals) and stripped down slightly. The torque on my clamp is low, must be about 20 NM’s (about the same as an oil sump bolt, no more). Have a look maybe that will help.

 

[Nibsy]

There are two approaches: work on it to get it fixed, which may mean paying somebody else or sell it.

I';ve watched the video but don't understand what connects on the other end - is there a similar metal ring on the adjoining piece so the clamp goes over both?

The clamp must squeeze some other part that deforms to take up space, seal the exhaust and hold it in place - that presumably is the copper piece since it is the softest metal.

I see the metal ring has a very thin section so the may be eaisly deformed - have you tried putting the copper ring over the thin section, as shown by the orange arrow?

As mentioned above, isn't there a similar steel ring that goes over the next section of exhaust the the clamp goes over? If so then maybe there should be two copper ring that when fitted, the two steel rings are slightly apart from each other and when clamped, are brought together so the copper rings deform?

View attachment 77721

Yes there is another flange ring on the fitting that it attaches to, the copper washer fits between the two, which are then held together with the clamping ring. The Yamaha schematic only shows one copper ring per header, in the position just described. I can see the theory behind this arrangement plain enough; it‘s supposed to work like a plumbing compression fitting,… but although the copper is a soft metal the force exerted on it by the clamp is nowhere near enough to deform the copper to seal around the pipe.

 

[Nibsy]

Hi Nibsy

I’ve had a look at mine (originals) and stripped down slightly. The torque on my clamp is low, must be about 20 NM’s (about the same as an oil sump bolt, no more). Have a look maybe that will help.

Yes that is exactly the set-up I have. But even with the clamp done up to the max the pipe is still loose. Thanks for the pics by the way.

 

[02GF74]

ok - good pics - so there are two loose flanges that are pressed by the clamp, these flanges in turn press on a copper ring - so as you, works like a plumbing compression fitting.

If doing up the clamps fails to secure the pipes, it can only be due to the copper ring being too small - if you cannot put a shim on the inside of the clamp (a strip of copper), then you may be able to find a thicker copper ring: a search for "copper compression exhaust rings " returns many results, you would need to measure the one you have and get same ID but thicker cross-section.

 

[Nibsy]

ok - good pics - so there are two loose flanges that are pressed by the clamp, these flanges in turn press on a copper ring - so as you, works like a plumbing compression fitting.

If doing up the clamps fails to secure the pipes, it can only be due to the copper ring being too small - if you cannot put a shim on the inside of the clamp (a strip of copper), then you may be able to find a thicker copper ring: a search for "copper compression exhaust rings " returns many results, you would need to measure the one you have and get same ID but thicker cross-section.

Yes that would seem to be the only option, other than using exhaust cement. I’m a bit cheesed off as the copper rings are genuine Yam and cost me £34!

 

[Screwloose]

Yes that would seem to be the only option, other than using exhaust cement. I’m a bit cheesed off as the copper rings are genuine Yam and cost me £34!

Hi Nibsy

Don’t feel bad about the money, I’ve been getting shafted all my life with car and bike parts. In the UK there are plenty of manufacturers and distributors that throw out complete crap, knowing that there are idiots out there like me that amend things to make them work.

I’ll need to start taking photos and notes of the work I do on my vehicles as my memory is poor, I done this job just last year and it’s only starting to come back a bit now.

I’ve read the couple of pages on your issue and the information is all there. When I worked on this exhaust I noticed that the strength for retaining the rear pipes comes from the clamping onto the collector box lower down, and the top section with the clamps and copper ring were fairly slack and could be pulled apart with a jerk. As the top pipe slides partly into the mating side, then the full force of the exhaust gas will not hit the copper ring, but in your case it appears (as above) the copper ring is not thick enough to hold back the low level gases pressure. Can I suggest something that has been already said, fit a shim ring to make up the distance that the copper ring is not taking up, If you cannot find one, there is a good chance I could make you one out of mild steel if I have some dimensions and sizes to work to.

Again; good luck.

 

[02GF74]

My understanding is that exhaust cement is to seal gaps for items already held together .... but I could be wrong ofcourse.

Have a search for "copper exhaust seal ring" on ebay - there are many from about £ 3 - measure inner diameter of the ring you have and then look for a thicker ring.

 

[Screwloose]

Yes that would seem to be the only option, other than using exhaust cement. I’m a bit cheesed off as the copper rings are genuine Yam and cost me £34!

Just had another thought. Have you tried two of the copper rings together, thus making up an additional thickness.

 

[Nibsy]

Hi Nibsy

Don’t feel bad about the money, I’ve been getting shafted all my life with car and bike parts. In the UK there are plenty of manufacturers and distributors that throw out complete crap, knowing that there are idiots out there like me that amend things to make them work.

I’ll need to start taking photos and notes of the work I do on my vehicles as my memory is poor, I done this job just last year and it’s only starting to come back a bit now.

I’ve read the couple of pages on your issue and the information is all there. When I worked on this exhaust I noticed that the strength for retaining the rear pipes comes from the clamping onto the collector box lower down, and the top section with the clamps and copper ring were fairly slack and could be pulled apart with a jerk. As the top pipe slides partly into the mating side, then the full force of the exhaust gas will not hit the copper ring, but in your case it appears (as above) the copper ring is not thick enough to hold back the low level gases pressure. Can I suggest something that has been already said, fit a shim ring to make up the distance that the copper ring is not taking up, If you cannot find one, there is a good chance I could make you one out of mild steel if I have some dimensions and sizes to work to.

Again; good luck.

Hi and many thanks for your help. I do have some shim-stock so i'll just have to play around I guess until I get lucky. I'm away for work for the next couple of weeks so it will have to keep for now...

 

[Nibsy]

Just had another thought. Have you tried two of the copper rings together, thus making up an additional thickness.

Definitely worth a go I guess.

 

[Nibsy]

Hi and many thanks for your help. I do have some shim-stock so i'll just have to play around I guess until I get lucky. I'm away for work for the next couple of weeks so it will have to keep for now...

I fitted a Black Widow stainless steel system to my generation 1 1996 bike and it fitted and worked extremely well, but it does use the standard rear headers because they are stainless anyway so does not solve that problem for you.

So you recommend the Black Widow system?? What silencer length did you go for? ... and how loud is it?

cheers.

 

[Stephan]

I did not know they did different silencer lengths! This was from about 2015. I must admit it is louder than I would like, but MOT testers do not seem bothered and it is not offensively loud. Here are some pictures of the system on the bike.

There is a lot more detail here if you are interested: Yamaha Vmax 1200 restoration by Stephan Morris

 

[Fire-medic]

That canister pair appears to offer a lot of volume, you should be able to throw-in a baffle with a smaller end diameter without costing you a lot of RWHP, I bet.