Faded Glory - 75' KZ400S

Last spring, i rescuedup a 75' KZ400S from some kid that wanted to "cafe" it.
Unfortunately for him, he "knocked up" his girlfriend, and had to sell all his bikes.  Lucky for me, I gave him $500, and even got him to deliver it.

When i picked it up, i wasn't sure what i planned to do with it...  worse case scenario, get it running, and flip it.
But heeer we are, almost one year later, I still have it, so i figured i should probably start a project.

Throught the next few posts, i'll recap what was done, and bring everyone up to speed.
Enjoy!
 

May 16 2021

Upon initial inspection, it had brand new tires, and everything appeared intact except the side covers and airbox.
The thing that initially struck me about the bike, was the paint...  It's in great condition, and sun faded in a way you could never replicate.
I've never liked red bikes, but i love the orange this one has become.

First step when buying any bike...  Change the oil, and rebuild the carbs.
When i went to look at it, the kid tried to start it, but fuel flowed out of the carbs like Bridal Veil in the spring.
Either way...  i don't care if they were recently rebuilt by Mr Mikuni himself, the carbs are coming off.

I ordered the carb kits from Z1, and did what i could while i waited for the kits to arrive (oil, plugs, check spark, check compression, etc.)



 

May 20 2021

Kits were a day or so out, so i started tearing down the carbs to clean them.

Not the worst i've ever seen, but definately in need of a rebuild.  As i dug into them i noticed a few things that were concerning.
#1 - one main jet was laying in the fuel bowl, the other was missing entirely
#2 - the pilot circuit on the second (right side) carb was mangled, and not coming out.
#3 - the slides were completely siezed in the bore
#4 - Both Choke plungers were stuck closed.

May 27 2021

The carb kits arrived, and i considered myself lucky for buying the complete kit which included all the jets, needles, and emulsion tubes.

I reassembled them with the new parts, set the baseline configuration, and crossed my fingers about the mangled pilot circuit.

First Start


Not Great, but it runs

After spending some time trying to dial in the idle speed, it was evident that the pilot circuit was not functioning on the #2 carb, as the mixture screw made aboslutely no difference .
Either way, i was going for a ride.

roll down my driveway, gentle turn onto the road, the bike lurches sideways, and i almost dump it.  Switch brain into diagnosis mode, and realize, every time i so much as lean the bike, the center stand is digging into the pavement.

Get back to my garage, and my hypothesis is proven correct...   the center stand is hitting the exhaust, and not able to fully retract.

At this point, i notice the petcock is leaking, so i drain what little fuel is left and make my to do list

To Do:
1: Get carbs sorted out
2: Troubleshoot Exhaust system
3: Source replacement side covers
4: Replace Petcock and add fuel filters

Cool bike!  Im partial to the 75 paint scheme, and I agree on the color of yours now.  Looks good!

I just removed my center stand.  If I need it, its not hard to temporarily reinstall it.

wrote:

Cool bike!  Im partial to the 75 paint scheme, and I agree on the color of yours now.  Looks good!

I just removed my center stand.  If I need it, its not hard to temporarily reinstall it.
 

Thanks!

I rely on the center stand too much to take it off, but I got it resolved.  I'll get to that, soon.

May 28 2021

When i was working with the carbs, i noticed the petcock was leaking, also it seemed the petcock was not functional.

per my Post on 5/23, it is nearly impossible to find a correct style replacement for this bike, without resorting to cheap aftermarket
I ended up going with a K&L petcock from a CB750, as it's physically the same, with 2 outlets, albeit different orientation.
Luckily Dennis Kirk is about an hour away, so orders typically arrive next day.

Old Petcock

Old and New

Fits fine

the fuel lines resemble a roller coaster now, but luckily physics doesn't care

one thing to note, both petcocks have casting marks for both orientation, so i don't know why K&L doesn't offer the straight outlet.

 

June 21 2021

Fast forward, haven't really made any progress on the carbs.  many posts on here trying to get information, as i have lots of Mikuni experience, but Keihin's were a mystery to me.
Figured i should focus on something that was within my control, The exhaust.

As i mentioned previously, the center stand was hitting the muffler, which caused it to drag, making the bike completely un-rideable (even if it isn't running properly)...
so i pulled the exhaust, and verified the center stand does indeed retract all the way.

Looking at the Mufflers, the brand is Sankei, and they're stamped KZ440A

Clearly these didn't fit the bike at the beginning, as evident by the hammer marks, from whoever "made them fit"

The exhaust had an H pipe installed, and i chose to retain it, and i chopped off the mufflers.

with the megaphones gone, there appeared to be an alignment issue between the two pipes, so i cut the crossover on one side and tacked it back together

With that sorted out, i tore it all apart and welded on some Emgo Shorties.  while not the best option, I'm too old for open pipes, and they were just the right size and length to allow the center stand to retract all the way.

dont judge my welds too harshly.  I was a few years out of practice, running on 110, and i didn't bother with any setup passes.  Just dialed it in on the fly.

At this point the bike starts and idles fine, so i captured the sound difference


 

July 25 2021

Up to this point, i've been spinning my wheels trying to track down a replacement carb that wasn't utter garbage.
in my search for carbs, i picked up a '74 KZ400D for $250. 

Sitting since '94, It has no title, and Minnesota doesn't like bills of sale, so it's likely destined to just be a donor.
all i needed was the Carbs, but the disc brake and starter, might come in handy.  who knows...

i yanked the carbs, they were NASTY! 
took a couple soaking sessions, to get them cleaned up, and my whole world collapses...
the number one carb is in better shape than what i had, but number two has a jacked up pilot circuit, the very issue i'm trying to resolve.
It appears someone tried to fix it in the past, and broke off a drill bit, or likely an extractor in the jet.

At this point, i'm at complete standstill until i can find a good #2 carb
The bike will start and idle, but there is no power at mid throttle.  best i can do, is idle with part throttle up and down my street.
can barely make it up my (steep) driveway without it bogging down.

one upside, these carbs showed me the parts i didn't know my original carbs were missing...
#1 there is a spring in the top to force the slide back down.  I thought it was just relying on gravity
#2 there is a metal tab that uses pressure from the bowl, to hold the main jet in place.  explains why mine kept falling out.
#3 there is a ball and spring to hold the choke lever in place