Backfire and exhaust leak!

My 1979 kz1000 has had exhaust issues since I got it. I cannot seem to get the headers to seal properly aagainst the head using the copper gaskets. The collars tighten all the way to the head and the pipes are still not very tight, and I can hear (and sometimes see) exhaust leaking out. There HAS to be a better way than these gaskets? or use two per cyl.? And when deccelerating I get major backfire. I am running straight pipes and pods, so I know SOME backfire is normal, but this is ridiculous! HELP!
Thanks!

Perhaps split collars are the wrong size (meaning not quite long enough) for these particular headers. Some headers have thinner flanges at the end which require slightly longer collars. Did the split collars come packaged with a brand new exhaust system?

Wouldn't use double copper gaskets.
Let's figure out exactly what's wrong.

Thicker gaskets are available as a last resort, but really shouldn't be necessary.

Good Luck!

The split collars came with th e bike, no idea if they're stock/ aftermarket. Where might i find slightly LONGER collars if I need em?

Contact Jeff @ Z1 for further detail in length available....

Redline has them as well but until you measure yours, hard to say...

www.redlinecycle.com/flanges.html

Z1 also has thicker sized copper exhaust gaskets....
www.z1enterprises.com/detail.aspx?ID=196

NOTE: One side of your copper ring is beveled... The flat side goes to the head exhaust port, the beveled side goes to the exhaust manifold pipe... You may want to confirm

when decelerating I get major backfire

This usually denotes too lean carb setting/jetting....

"running straight pipes and pods"... Was this configuration on there previously or is this something new to your ride you've installed?

If new, then you'll most probably need to re-jet your carbs....


OMR

on a diffrent note but same theme.....i just spent some time getting down with my exhuast issues ....once my bike had fallen off the center stand sofly forward onto the pipes....only later while fixing a previous exh issue did i find that when freed up the pipes had a new tweek at the ports.....i found that one of my top header flanges needed a "pop" with my palm or a tap with a rubber mallet to make it a good linning up to the copper gaskt/o-ring before the flanges and coller went on.....as for your dilema my split collers are also drawn tight and i start to bottom out the collers "just" as the nuts get tight....suzuki exh gskts are thicker and z1-e has em the look silver and have materiel emmbedded.........i might find an extra split coller to measure length on a stock one today and repost......good luck you'll get it right......unburned gas from seperate fuel mixture/jetting.. issues gets burned in the header and goes "BANG" or POPS imo.....best of luck...peace craig

Nick, random thoughts. first, the exhaust 1/2 moons (collets )are directional. the skinney end goes into the head. with the turned over lips fitting to the fitting plates.2nd, some after market pipes incorperated additional spacers which were used in conjunction with stock collets which may be missing. once pipes are introduced to head sealing areas should get snug long before running out of threads, even with pre-crushed exhaust gaskets. 3rd, if the easy fix is to double up w/ exh gaskets, why not? additional gaskets won't restrict flow, and straight pipes wouldn't care any way. exhaust leaks along with being annoying can lead to burnt valves. hope this helps,G

nickcycle wrote:

The split collars came with th e bike, no idea if they're stock/ aftermarket. Where might i find slightly LONGER collars if I need em?

Another possibility is that the existing split collars had for whatever reason been ground shorter.

This could have conceiveably resulted from an attempt to wrongfully assemble them by fitting with the flanged end toward the engine instead of correctly positioned with the flanged end nested inside the exhaust clamp.

I seems to me that a single gasket is preferable because it allows the flanged end of the exhaust pipe to rest inside the exhaust port on the engine head whereby the system may better self-align and be better supported at the head area without depending solely on the studs and clamp. Not to mention the extra difficulty of holding not one but two gaskets in position during reassembly.

As they say in army training, with your right hand hold part A, with your left hand hold part B, with your other hand . . . :laugh:

Good Luck!

Thanks ALL! I have tried most of these already, doubling gaskets, etc, even made my OWN gasket out of 20 guage copper sheet, a donut to fill the entire exhaust ports, but no luck. Think I just have to try to get some longer split-collars. And the bike came to me with the pods and open 4 into 1 system, but there's no guarantee it was re-jetted to match. I'll hafta dig into that one too.
THANKS

SUCCESS!! This time I used 2 gaskets, stuck em together with exhaust putty, and used the putty to stick em in the head. NO LEAKS, no popping on decel, exhaust note even sounds better, like a Ferrari!!! And TAKE YOUR TIME, make sure everything is lined up. Jiggle the end of the muffler a bit as you tighten the collars, and everything should be kosher.