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Z1 Baffles

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sneck
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Z1 Baffles

#1 PostAuthor: sneck » Sat Oct 01, 2011 8:52 pm

I am trying to help out ode lad who came round today, His Z1b has standard
pipes on but it sounds loud he has removed the baffles to investigate but they all appear to be different and he is trying to determine which one (s) is right
has anyone got any photos and dimension so he can then check which one is right and then correct the ones that aren't

Thanks Sneck

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#2 PostAuthor: z1bman » Sat Oct 01, 2011 9:13 pm

according to the parts manual all the baffles are the same

http://www.babbittsonline.com/kawasaki- ... B_Z1_(1975)/AIR_CLEANER%2f%2fMUFFLERS/Z1-B-1975/070060C-8

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#3 PostAuthor: sneck » Sat Oct 01, 2011 9:33 pm

z1bman wrote:according to the parts manual all the baffles are the same



What I should of said is someone at some point has had a go at making / modifing their own and that is why they appear to be different ,

Anyone with a photo and dimensions of the correct looking baffles ?

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#4 PostAuthor: z1bman » Sat Oct 01, 2011 9:55 pm


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#5 PostAuthor: sneck » Sat Oct 01, 2011 10:22 pm



Struggling with the link

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#6 PostAuthor: Garn 1 » Sat Oct 01, 2011 11:25 pm

Sneck, if you could possibly post a picture of both, we would quickly be able to identify the offending baffle. To my mind there were several types of baffles.
With ref to Z1B link, you can see this is the type with the solid tube. Some of the early baffles were made of perforated metal formed into a tube, on the later, this appeared as a solid metal tube with a series of holed drilled in it.
RegardZ.
Garn (Sydney) Z1, Z1A, Z1B and Z900-A4

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#7 PostAuthor: Hack » Sun Oct 02, 2011 6:20 pm

Are the standard pipes genuine Kawasaki or pattern pipes?

I made some rough drawings when investigating the over loudness of my pattern pipes (now resolved), I'll see if I can dig them out.

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#8 PostAuthor: Hack » Sun Oct 02, 2011 6:50 pm

Found my old drawings - a bit rougher than I thought!

A couple of the dimensions slightly contradict each other but may be of some use to you. Can't find any info relating to diameters - I'll keep looking.

These are from a pattern set of pipes circa 2006ish
One of the baffles has a shorter length of wading (Upper left I think but not sure) as the chamber inside the silencer is shorter for some reason which escapes me at the moment.

Cheers,
Andy

Image

Image
Last edited by Hack on Sun Oct 02, 2011 6:58 pm, edited 2 times in total.

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#9 PostAuthor: PAULJAC47 » Sun Oct 02, 2011 6:52 pm

A4 Baffles have less drillings than the earlier types!!
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#10 PostAuthor: sneck » Mon Oct 03, 2011 8:53 pm

Thanks Andy the drawings with measurements are what is needed


Sneck

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#11 PostAuthor: Hack » Mon Oct 03, 2011 9:45 pm

Sneck, are the pipes genuine or pattern?

If they're pattern I'm pretty sure I know why they are too loud - a (very)long story but mine are now sorted!

Andy

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#12 PostAuthor: RogerJ » Tue Oct 04, 2011 7:53 am

There was another thread on the site a while back re. baffles. As I was checking mine out at the time, I copied it into a MS Word document. I cannot remember who posted it originally, but the contents are:-

This is for the thinkers amongst you, the rest can look away now (just joking!).

I fitted a new pattern 4-4 exhaust to my Z900A4 last summer and found that it was way too loud (in my opinion), i.e. much louder than any standard exhaust I remember from my younger days. I initially thought this was due to a faulty baffle and the pipe in question was replaced by the supplier. The new pipe is a bit quieter but it still seems too loud.

The general perception is that the pattern systems are constructed in the style of the original Z1 with removable baffles, unlike the KHI genuine pipes which are the more restrictive (and quieter) 1976 version.

Well, after a bit of investigation with an endoscope (ooh err missus!) I have concluded that this is not true and that the pattern pipes have the later 1976 internals but have the original 1973 design baffles fitted. The upshot of this is that there is even less restriction than the original design. See the diagram below (sorry for the file size and the poor drawings).

In each case the gas enters from the left and exits on the right.

Fig 1 shows a standard Z1 exhaust.
Exhaust gas passes from A into the baffle pipe until it meets the blank mid-way along B, it then enters chamber B where some passes back into the baffle beyond the blank and some goes via the balance pipe to chamber B of the associated exhaust. The wadding and small holes in the baffle at chamber C are only to absorb sound (like the induction silencer on Z900A4 air filter), no gas passes into chamber C.

Fig 2 shows a standard Z900A4 exhaust and apart from the shape, this system is completely different from the original Z1.
As the baffle pipe blank is located at the extreme LHS all exhaust gas passes via a tube from A directly to C, the gas then turns 180 degrees and passes through another tube from C into B. At this point the gas splits with some entering the baffle tube to exit and some passing via the balance pipe to B of the associated exhaust.

Fig 3 shows (my) pattern exhaust (1976 construction with 1973 baffle)
If you look at this you will see that the gas can get out just about anyway it chooses!! No wonder it seems loud.



Am I right?

Am I the only one to have come across this?

The bike looks good and runs great - “ better than with the previous 4-1 system

I'm still researching this at the moment so don't leave your pride and joy where I may stumble across it as I never leave the house without a gas-axe and a petrol driven angle grinder!

What's the solution?
It would appear that without much effort I could adapt the baffle or blank off the inner pipework to achieve either of the original designs although I'd like to think the manufacturers should address the issue (no chance).
I could live with it - “ most likely.

Mark,

I've just dug out the notes I made last year when I was looking into this and on the baffles supplied in my pattern pipes the blank is 155mm (6 1/8") down the pipe, i.e. midway down chamber B.

The total baffle length was 236mm (9 1/4") which seems to suggest that your baffles have the blank at the very end, which as you point out coincides with the first baffle plate, i.e. you appear to have the later design.

I'm pretty sure there was yet another silencer design in between the 73 & 76 models but I have no idea what the insides look like as the KHI genuine manual only shows these two.

Andy



There are at least 6 main variants of the 4-4 pipes. I'm not close to 100% sure on when they all appeared as I've seen too many contradictory bikes.

no stamping and no stainless cover over the weld between the header and muffler
no stamping and a stainless cover over the weld between the header and muffler
small stamping and a stainless cover - KHI 900 Z1/750 Z2
large stamping and a stainless cover - KHI 900 Z1/750 Z2 DGM 13236S
76 stamped after KHI 900 Z1/750 Z2 DGM 30386S (original KZ900 pipes)
76 stamped on the pipes and NO stainless cover, zinc paint instead (current replacement pipes)
I've seen sets of the 2. pipes on frame numbers as high as Z1F-07xxx
I've seen 3. on 73 and 74 bikes
I've seem 4. on late 73 and 74-75 bikes

I've seem mixes of 2, 3 & 4 pipes on bikes. I've heard customers who've owned the bikes from new state things that don't make sense... but one thought on bikes being sold at a dealership - some pipes would have been damaged in transit. When this happened the dealer would replace them with stock from Kawasaki inventory - which in all likelyhood would have been imported way before the bike was - so I can see how earlier pipes make there way onto later bikes coming out of a dealer.



Hi justin,
The 76 stamp on the pipes were for the Z900A4 which was the 1976 model, hence 76. The only difference as far as i know is in the baffles. The pipes had to be quieter to meet the new noise regulations. My last A4 had 76 pipes on one side and z1 (un stamped ) on the other. If you listened carefuly on tickover you could tell the unstamped 76 were slightly louder, but most people would not notice. i believe the very early ones had baffles that could not be removed, then the next ones had a bar fitted so you could hook(pull) them out. Its all down to you if you want 100% originalty. They all work the same.
Roger

Ex Fat Rabbit

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#13 PostAuthor: RogerJ » Tue Oct 04, 2011 8:26 am

Sorry that the embeded pictures of the baffles didnt materialise in my previous post, I have saved them as a photo:

Image
Roger



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#14 PostAuthor: RogerJ » Tue Oct 04, 2011 8:30 am

PS. The original post was from Hack in May 2008.
Roger



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#15 PostAuthor: Hack » Tue Oct 04, 2011 5:11 pm

Well spotted RogerJ

Yes it was my post back in 2008 and they are my drawings.
As you can see the issue was fairly complex but only relates to pattern pipes hence my asking sneck what is fitted to the bike with the current noise problem.

I spent ages getting to the bottom of my problem but the nutshell account is as follows:

Pattern pipes are the later 76 A4 design internally.
The baffles fitted to the pattern pipes are the early type (Z1/A/B?).
The two things are not compatible and can never sound right!!!
I modified my baffles to make them as per 76 design - can provide details if anyone is interested.
For the 76 design the gap between the baffle flange to silencer matters and one of mine was particularly bad, sealed with high temp silicone. This gap on the earlier models doesn't matter as there is no pressure in the final chamber.
It sounded like a tractor before but now sounds absolutely spot on!

I've got to let this go - I'm becoming an exhaust anorak!

Andy


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