'81 Kz650 exhaust crossover nipple broke

My '81 Kz650 has a crossover tube on the stock exhuast system between the left and right 2-into-1's. We've all seen these crossover tubes that connect the left side 2-into-1 to the right side 2-into-1 on stock KZ exhaust systems.

I went to remove the entire exhaust for cleaning and the crossover 'nipple' on the right side pipe was cracked where the nipple clamps into the crossover tube.

The part of the right exhaust's nipple that fit inside the crossover tube -- is *still in the crossover tube*, ie. the nipple for the ride side broke right at the junction of crossover tube and right side exhaust during removal of the system for cleaning.

Bike is losing power, is loud in an uncool 'there goes a homeless guy on a bike' sort of way. Definitely not a cool sound. People would give me money should I stop, 'Here buddy let me make a donation to your exhaust leak there, awful sorry to hear your in a bad way.'

There is enough remaining nipple on the right side pipe, if I could just find a short pipe that would fit inside the remaining nipple on the right side, I could slide the other end of this short pipe into the crossover tube.

Is there another way?

thats abut the easiest answer i can think of

Thanks, Plummen for the confirmation there.


There's not enough metal left to weld something on without semi-major surgery on the right side. However if I can get lucky and scrounge up a pipe in the correct diameter to fit inside the nipple, I should be good.

My big problem now is -- I have no idea where to find a pipe for a 'join' to re-connect the crossover to the right side.

Another solution is to scour ebbaayy for a replacement crossover pipe.

martin_csr wrote:

Another solution is to scour ebbaayy for a replacement crossover pipe.

I wish it could be that easy. The actual crossover pipe is fine. It is the 'nipple' that sticks out from the right side 2-into-1 exhaust system that is broken. This nipple sticks out from the right half of the stock exhaust system and plugs into the crossover tube. (The right half of the exhaust has a nipple also that plugs into the crossover tube. Luckily that side is fine.)


When I removed the exhaust for cleaning, the nipple broke in half -- part of it is still inside the crossover tube, and only a stub remains on the right half of the stock exhaust.

If anyone can suggest what type of store or vendor that has piping of varying diameters that would be cool. Welding is probably not an option, not enough metal on the right half to weld to (rust caused the original crack and ultimate break-off of the right side nipple).


I looked on ebay earlier and found an exact matching stock system for my 1981 CSR kz650:
cgi.ebay.com/ebaymotors/1981-KAWASAKI-KZ...&hash=item43a546b2ab




This ebay seller says 'No Rust', wow, good eye.

Here is the enlarged view of his system -- his right nipple is rusted quite a bit, apparently rusty nipples are a problem for this model.:blink:

Okay, my mistake.

Check out this one:

NOS Right Side

newOld_kz1000 wrote:

Thanks, Plummen for the confirmation there.


There's not enough metal left to weld something on without semi-major surgery on the right side. However if I can get lucky and scrounge up a pipe in the correct diameter to fit inside the nipple, I should be good.

My big problem now is -- I have no idea where to find a pipe for a 'join' to re-connect the crossover to the right side.

check bargain bin at local welding shop

650ed wrote:

Check out this one:

NOS Right Side

Thanks 650, I would jump on it if this particular 650 was in that kind of condition. I paid $50 fer the darn thing. It was not worth much more. Although it's only showing 17,300 miles, it was left outside.

Yesterday I had to completely disassemble the rear brake hub because the brake shaft (the shaft that pushes the brake shoes out to the hub sides to stop the bike) -- the brake shaft was frozen solid in its bore in the brake shoe housing. Despite gaskets on the outside where the rear brake arm connects onto that shaft, water somehow got inside the brake shaft's hole in the brake housing and rusted the shaft so it stuck to the housing. Such is the poor water-exposed condition of this bike.


If this was a cherry bike no way would I have got it for $50. Right now, there's plenty of visible rust on the frame and frame paint peeling, all the aluminum engine parts are oxidized, the gas take looks bad -- I feel stupid spending $40 for the used seat I just ordered. Its gonna take a big chunk of $$ to get this thing right, and I just want a rider.

That part you found is exactly what I need, it would though make the remaining part of the bike look worse due to the contrast.

I very much appreciate you help, thank you.

Okay I think I got lucky on the I.D. (inside diameter) of my Kz650 exhaust -- I took the right half 2-into-1 with me to the local hardware store, plumbing section, and after messing around I found this:




This darn thing actually screwed right into the right side stub that was left after the nipple broke off. And the unthreaded side slides right into the stock crossover tube.

I'm headed out to reinstall the system but I think this $4.19 piece of copper done the trick here. Kawasaki/Sankei meet modern plumbing code. or something.

Okay sometimes cheapass tricks do work.


Here is the nipple before installation -- notice the pretty deep amount of threads on the threaded end:



Now here is the copper nipple replacement piece screwed completely into the right side exhaust 2-into-1 -- note that I buried the entire threaded part of the copper into the broken Sankei nipple there -- and I DID NOT have to tap this, I just screwed the sucker right in there as if she was pre-tapped waiting for copper:


Okay here is an important part (I feel) that made this jury-rigged plumbing repair work. I did NOT remove the broken-off tip of the right exhaust's nipple from the crossover tube. You can see the nipple tip is still inside the clamp -- I prepped the broke-off tip with the closed head of a pair of pliers to smooth off the rough edges of the inside diameter of the broken tip so the copper nipple would fit in easily:




Okay so here is the repair copper nipple installed:



Now the installation of the right side exhaust was E-Z -- I just put the head pipes in the exhaust ports on the cylinder, lined up the copper nipple to the crossover tube and pushed the copper into the crossover. Then I just re-tightened the clamp. Then put the rear of the muffler's bracket back onto the rear passenger footpeg where is normally is.


AND THE SUCKER WORKS GREAT. So this was a cool day.

This 650 runs a LOT better with that exhaust repaired.
I pulled and checked the plugs after she cooled down -- the ceramic tips are golden brown, real nice.

However I am pretty sure I have a clog(s) in my low-speed jets in one or 2 carbs, she drops a cylinder, sometimes two, at idle. I will get to that directly.

But when I get on the throttle, I can feel that accelerator pump kick in -- it's like a mini-turbo boost. I think this is making more power too, maybe the piston rings are back to normal, because it feels like it's got a lot more power, so much so that I notice the clutch slipped once when I really got on it. Have not until now experienced that.

$4.19 and it's time to move on to my long list of rehab stuff to do on this fine machine.

id clean up around it with some sand paper and maybe smear a little clear silicone around it to seal it up