KZ750 Exhaust

I have a Delkevic 4 in 1 exhaust on my 1980 KZ750H and it's quite loud. I went to get my MOT today and it passed the stationary noise test (91dB at 0.5m away from the end of the muffler - maximum was 103dB) but the guy said I needed to do a test under acceleration. The test will set me back up to €300-350 so I'm rethinking the whole thing. My main problem is that I actually find it too noisy when I'm riding and I don't think it will be very long until I want to change it.
I would like to go back to the 4-2 stock system but it is hard to find them in good nick. I was wondering if I could use the Zephyr 750 stainless steel headers from Black Widow ( www.blackwidowexhausts.co.uk/kawasaki-zr...es-headers-450-p.asp ). I know the headers will fit, but I'm wondering if the Zephyr mufflers will line up with the stock footrest brackets or whether I could even use stock mufflers (I think the header turns out too far for this and the mufflers will end up being miles away from the brackets, but I'm not sure).
I have found a couple of similar posts but no real answer as to what options/combinations will work for the 750E/H.
Anybody used Zephyr pipes on a 750E?

Maybe even a stock Kz650 from a SR or CSR model?

True, they should be just a straight swap. Thanks, one more ebay search to keep an eye on

Why not install a quiet baffle? You could even make one if need be. The Kawasaki version Kerker baffle was quiet, or they had a quiet option anyway. That would be a fun project.

You're right, it would be a fun project. Problem is lack of experience and tools. It's something I'd like to do but not something I want to try and get done before being able to ride my bike. Another downside is that I still need to get it tested, but it may be a bit easier to get through just on the stationary test if it's not that noisy.

I did look at the baffle and it's about 10cm shorter than the pipe. I thought about getting some stainless mesh tubing and wrapping it with fibreglass. I could then shove it in the end of the collector up to the bend and whack the muffler over the top. Would end up being about 15cm in length. Wasn't sure if this would affect flow/back-pressure though. Also not sure how much difference it would make.
Any idea how small I could go on the tubing? The exhaust to collector fitting is 64m and the stock baffle is about 30-35mm in diameter.

I found this today and thought I should post it in case anyone else is looking into Zephyr exhausts:

www.z-club-germany.de/10-Download/Extern.../Z750LTD/Auspuff.pdf

It's in German, but the pictures should be enough. Basically, the Zephyr 750 header will bolt on to the KZ no problem. If you have a centre stand, however, you will need to extend the pipe joining the two sides by 25mm (as seen in the photos). I'm not sure if you can skip this if you don't have a centre stand, but I would assume so. I would probably put a larger pipe over the top and weld it on, the guy puts a pipe down the middle (dia. 24.74mm) and mentions that you should cut some slots on the outside pieces and clamp them down.
The muffler brackets don't quite line up so the guy just drilled another hole in them. He also mentioned that he mounted them on the outside of the brackets. That means they should fit behind the brackets fine if the headers aren't widened (i.e. if you don't have a centre stand). This was the bit I was concerned about, I really wasn't sure that the muffler brackets would line up at all.

Should be possible to take out the Delkevic muffle and have something around it to reduce the noice?

The baffles on the classic mufflers are already wrapped (the are made with two concentric cylinders packed with fibreglass and sealed at each end). The only real chance is to extend the baffle. I would do this if I thought it would help me avoid the more expensive of the noise tests, but it's not looking good.

Another factor is that I originally wanted a stock exhaust but just couldn't find any in good enough condition (in hindsight, I should have waited a bit longer as a couple came up that were OK, but the budget was blown). Basically it boils down to either making the Delkevic quieter and getting tested (probably €300-350), or selling the Delkevic and getting another system pre approved for road use (in total probably about the same cost if I get a new exhaust).

I looked at that video again and then had another look at the megaphone silencer from Delkevic:
delkevic.co.uk/kawasaki-kz750ltd-1983-fu...aphone-silencer.html

It has two baffles: the outer baffle, which is just a packed cylinder like the one in my silencer, and the inner baffle which is the same as the one in the video. This setup is supposed to be quieter as-is, but I could pack the crap out of the inner baffle and it would probably be pretty good.

Worth noting: this thing has been on my e-bay watch list for almost a year I've been tossing up whether to get it as I think it is a better style for my bike. Stay tuned...

Have a look at these pipes
www.kijiji.ca/v-motorcycle-other/kitchen...0-exhaust/1496255675

Damn. In north-western Canada I might have been able to swing it... Thanks anyway.