Exhaust choice


CBX1000chris
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Exhaust choice

Post by CBX1000chris »

Hi everyone and belated Happy New Year.

My bike started blowing on the left silencer and I finally got around to looking at it, big hole and loads of rust.

I want to replace it with something that looks original so I think my choice is either the David Silver silencer for £1267 or the Delkevic for £1400. Can anyone let me know if there is anything to choose between them please and if there are other options I'm unaware of.

Thank you in advance,
Chris.

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shiskowd
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Re: Exhaust choice

Post by shiskowd »

I purchased as set of the replica exhaust that CMS (CMSNL.com) sells for 1,195(EURO). Exact fitment and well constructed. These may be the same ones that David Silver sells, don’t know for certain.
2022 KTM 890R, 1982 Pro-Link, 1979 CBX 'Z, 1975 Moto Guzzi 850T
Long Sleeping '79 CBX Restoration > viewtopic.php?f=102&t=11699

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Re: Exhaust choice

Post by NobleHops »

shiskowd wrote:
Sat Jan 22, 2022 2:23 pm
I purchased as set of the replica exhaust that CMS (CMSNL.com) sells for 1,195(EURO). Exact fitment and well constructed. These may be the same ones that David Silver sells, don’t know for certain.
You are correct there, I bought a set from DSS very recently and it arrived in a CMS box with duct tape on the logos. I had a laugh!

I personally think the two are equivalent, but some say the CMS/DSS sets fit better and are closer to original. I have Delkevic on my own 80 and have used both, think they're both excellent.

N.
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Re: Exhaust choice

Post by jnnngs »

Hi,

As Nils says, the DSS and Delkevics exhaust systems are both very good.

I find the downpipes on the Delkevics "blue" very slightly, not enough to be a problem but do lose the new chrome look.

The centre baffle protrudes more from the end cap of the silencer of the DSS ones. (some one said that you can fix / change that, no
t tried tho)

Paul.

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Re: Exhaust choice

Post by wyly »

I may be wrong but I thought the replica's sold by Bert at SCM were a Sankei re-issue, double walled headers to avoid bluing like the originals.
1,445.95 euros.
https://www.sixcenter.nl/onderdelen/det ... 47&start=0

I don't know if they're the same exhaust as sold by CMS
CBX a work in progress, still improving...GS1150EFE completed and awaiting modifications.....RD350, remnants in boxes scattered throughout the garage

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Re: Exhaust choice

Post by daves79x »

All the reproduction exhausts mentioned above are double-wall. All of them will blue the headers if the bike is left fast idling on choke, just like the stock exhaust.

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Re: Exhaust choice

Post by 512tr »

Are there any good internal coatings on the market that really works to avoid blue headers?

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Re: Exhaust choice

Post by daves79x »

All single-wall headers will blue. No double wall ones will blue if you don't fast idle on choke.

Dave

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Re: Exhaust choice

Post by Larry Zimmer »

Steel blues in the 500F to 600F range. Can't be avoided with single wall. Double wall will keep the outside tube cool enough if you do as Dave said. Note: steel will start to turn yellow at 350 to 450. So, if you want to keep your double wall (stock) pipes shiny chromy, get off the choke pronto!
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Re: Exhaust choice

Post by Jeff Bennetts »

512tr wrote:
Fri Feb 04, 2022 3:36 am
Are there any good internal coatings on the market that really works to avoid blue headers?
Yes, but they won’t stick to the inside of the pipes unless the pipes are squeaky clean. A new system will have the best results but you still need to clean them from any oils, grease or whatever left over from the manufacturing process. The cheap way to go is buy some PJ1 or the like, the High Temp paint and coat the inside of the header pipes!

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Re: Exhaust choice

Post by 512tr »

Thanks for the reply,
I do have a set of Dyno-Kote bought long time ago, it’s some ceramic thick milky like stuff.
Any experience with Dyno-Kote?

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Re: Exhaust choice

Post by CBX1000chris »

Afternoon everyone,
Well I bit the bullet and ordered a full exhaust system from David Silver, it is "Identical to the original appearance" apparently so what could possibly go wrong......
The packaging had been doctored, in fact surgery had been performed, to remove the top layer of cardboard. Sadly the surgeon was pissed and he made a poor job of it, you can still see the remains of the CMS logo. This doesn't bother me but it is slightly bizarre!
20220211_104339_1.jpg
I fitted the right side first and it was a bit weird to see the stamped numbers on the underside of the collector box being wrong. Cylinder 6 is stamped 1, 5 is stamped 2 and 4 is stamped 3. Looking at the left side exhaust cylinder 1 is stamped 4, 2 is stamped 5 and 3 is stamped 6. However the stamping is on the underside of the collector so out of sight. If I'm honest this lack of attention to detail would normally ring alarm bells for me, we are talking about 1260 of your finest British pounds. However, onward!

The right side fitted pretty well really, the only concern being the length of the studs in the head for the clamps, this was a problem with my old exhaust too so not related to the new system. I might have to resort to shortening the collars by 3mm so the thread protrudes fully through the nut. I am puzzled by this though, any ideas anyone? There is only one gasket in the port!

Now to the left side exhaust. The first problem came to light when I tried to put a bit of tension into the number 2 exhaust pipe clamp to stop it wobbling about, I had to really tighten this to get any effect, even then it was still loose. Positioning the exhaust on the bike the next problem was the heat shield clamp was fouling on the footrest bracket, I managed to loosen it and move it a tiny bity but it's not good.

When I was bolting it all up I noticed that one of the silencer bracket studs was very close to the swing arm,
20220213_112250_1.jpg
also, the side stand completely misses the rubber bump stop and hits the metal bracket.
20220213_111302_1.jpg
Comparing the old and new exhaust rubber stand stop brackets they are quite different. On the original exhaust the side stand bracket is rotated around, not so on the pattern part. Also, the side stand bracket is shaped to accept the oblong rubber on the original part, on the new exhaust both brackets are the same. I think the manufactured has fitted the centre stand bracket in both positions and got one of them in the wrong place.
20220213_113232_1.jpg
I decided to try fitting the mounting bracket off my original pipe to the new exhaust to see if things would improve and actually they did. The stud on the new exhaust was further away from the swing arm and the side stand just catches the rubber bump stop. One other thing, with the old bracket the exhaust was 5mm further away from the tyre than with the bracket supplied with the new exhaust so the exhaust has moved 'outward'.

When the left exhaust was fitted to the bike I tightened the number 2 exhaust pipe clamp bolt as much as I dare but when I removed the exhaust from the bike the pipe was still loose and would probably blow when the engine is running.

Needless to say I'm very disappointed with the exhaust system and will be contacting David Silver Spares tomorrow. My initial worries about attention to detail proved to be a reality.

Am I just unlucky, pedantic or a whinger?

Back to the question about the length of the exhaust pipe studs, has anyone else encountered this problem and if so what did you do?

Thank you in advance for any advice.
Regards,
Chris.
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Re: Exhaust choice

Post by NobleHops »

You’re not a whiner, clearly there’s a problem. I have a very recently purchased set, hope it’s not similarly goofy. Contact DSS for sure.
Nils Menten
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Re: Exhaust choice

Post by daves79x »

FWIW - the configuration of the stand bumpers on the '79 original 422 exhaust is just like the pattern one - two round rubber stops. Your rectangular one on the stock pipe appeared with the 469 systems. Not really related to your other problems, but just info. Again, FWIW, make sure your sidestand is perfectly straight.


Dave

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Re: Exhaust choice

Post by shiskowd »

daves79x wrote:
Sun Feb 13, 2022 10:28 am
Again, FWIW, make sure your sidestand is perfectly straight.
The only issue I had with my CMS set was that the side stand didn't contact the rubber stop, that is until Dave pointed out that my side stand had developed a slight curve. Straightened it out and now aligned perfectly with the stopper. Other than that the pattern set slipped in without any fuss.
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Long Sleeping '79 CBX Restoration > viewtopic.php?f=102&t=11699

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