Faded Glory - 75' KZ400S

Nov 7 2021

Months have passed, and i've had no luck sourcing a good working carb.  I've spent time doing little things like replacing the grips, checking the fork oil, but nothing substantial.
The time has come to put the bikes to rest for what will be a really long winter.

from left to right: 1980 XS1100, 1969 Trail 70, 1970 Trail 70, and the KZ

Welcome to the Present!
It's still too cold to ride, and it snowed just a couple days ago, but i finally made some progress!!!

Last week i got a hit on Ebay, a set of Keihin CVB36.  judging by the picture, everything looked straight, so i messaged the seller, asking if he could confirm the pilot jets were free.
he responded the next day with pics of the pilot jets removed.  SOLD!

I was not happy having to shell out $196 (170 pus shipping), but he wasn't open to offers, and i'm desperate.
They arrived yesterday, and i immediately took them to the garage to start the rebuilding process, when my heart sank!
These are from a different bike, with closer spacing.

here's the two intake manifolds side by side for comparison

That being the case, the linkage is different

new carb on the left, kz400 carb on the right

other than that, the carbs appear to be identical, so i tore them down to clean, and resigned myself to swapping the linkages.

It took me several hours, making sure that all the little pieces didn't get mixed up, but i managed to get it done...

Linkage dissabled side by side

Installed back on the bike, it sounds completely different, and idle no longer races towards redline.
Currently stable idle just shy of 2k, definatley needs a sync, but that will have to wait for another day. 
It's been raining nonstop, supposed to continue all week, and i'll be out of town all weekend.
Fingers crossed for better weather soon.

Very glad that you finally got a good carb set, even if it took a lot of work!

wrote:

Very glad that you finally got a good carb set, even if it took a lot of work!
 

Fingers crossed
There's two other differences i failed to mention...

First, the choke port appears to have a reducer installed.  not sure if that will make a difference, since i'm using a mismatched set at this point. if it does, i assume it would only matter during warmup, if the choke is engaged.

Second, since i'm not sure what model bike these carbs were set up for, i'm not 100% positive about the pilot jet size.  there didn't appear to be any markings.
either way, it's 110% better than it was

Snowed again yesterday, but got up into the high 40's today, so i spent some time after work syncing my carbs.

Luckily they weren't that far off to start with, so it didn't take too long to get them dialed
Little bit of flutter on the right (in the pic), but they're pretty much dead on.

One of these days i'll get myself an auxiliary tank...
For now, a broomstick and clamp did the trick

I had been using a couple craptastic pods that i had laying around (think they came with another bike), because something is better than nothing...
Put the Uni's on today

Also, installed the side covers for the first time, since i got them last summer.

I like the faded one, I think it fits the aesthetic...
The one on the right is a little too "red", but it's got a big crack next to one of the mounting tabs, so it may get replaced at some point.

Took it out for a quick run down the street...  managed to hit 50mph, which is a first.
I installed the 6Sigma kit, which came with bigger main jets, and shims for the needle. 
with their reccomended settings, it pulls really good, and the mid throttle bog is gone, but is really rich, so some additional tuning is in order.
will need to play with the shims, maybe drop down from 50 to 40 on the main jet...
hard to say though, since its still really cold out.

Funny story:
I left my driveway, was pretty excited how much better it was running.  a few blocks down the road, right as i was about to pat myself on the back, it starts surging, i downshift trying to keep it running long enough to coast to safety...  I miss neutral, it dies while i'm in the middle of the street.  I had to find neutral, hop off, and push it to safety, while annoyed drivers glare at me.

So there i am, sitting on the side of the road kicking and troubleshooting, and i realize...  the petcock was off
guess i turned it the wrong way as i was leaving my house /Facepalm

luckily i didn't have to push it home, uphill the whole way.

Great photos explaining everything you've done!  It's surprising you couldn't find a decent set of replacement carbs.

wrote:

Took it out for a quick run down the street...  managed to hit 50mph, which is a first.
I installed the 6Sigma kit, which came with bigger main jets, and shims for the needle. 
with their reccomended settings, it pulls really good, and the mid throttle bog is gone, but is really rich, so some additional tuning is in order.
will need to play with the shims, maybe drop down from 50 to 40 on the main jet...
hard to say though, since its still really cold out.

Funny story:
I left my driveway, was pretty excited how much better it was running.  a few blocks down the road, right as i was about to pat myself on the back, it starts surging, i downshift trying to keep it running long enough to coast to safety...  I miss neutral, it dies while i'm in the middle of the street.  I had to find neutral, hop off, and push it to safety, while annoyed drivers glare at me.

So there i am, sitting on the side of the road kicking and troubleshooting, and i realize...  the petcock was off
guess i turned it the wrong way as i was leaving my house /Facepalm

luckily i didn't have to push it home, uphill the whole way.

I built a KZ650 for my son last year, I explained the whole running out of fuel scenario and to turn the petcock to reserve , blah blah blah. Rings me from the side of the road a week later broken down, explained the coughing , jerking then nothing, I asked if he'd run out of fuel and to put the petcock onto reserve, he says that there's plenty of fuel in the tank.  He rang me 30 minutes later from home, yep, put it on reserve and rode it home....Happens to the best of us....!!!

The old Kaw gas tanks used to store a bit of fuel on the right side of the tank.  After running out of fuel I once took the tank off and tipped it to move that fuel to the left side.  It was enough to get me to a gas station.

wrote:

The old Kaw gas tanks used to store a bit of fuel on the right side of the tank.  After running out of fuel I once took the tank off and tipped it to move that fuel to the left side.  It was enough to get me to a gas station.

Honda 750/4's were the same, Lay the bike over, get an extra mile or so....

wrote:

I built a KZ650 for my son last year, I explained the whole running out of fuel scenario and to turn the petcock to reserve , blah blah blah. Rings me from the side of the road a week later broken down, explained the coughing , jerking then nothing, I asked if he'd run out of fuel and to put the petcock onto reserve, he says that there's plenty of fuel in the tank.  He rang me 30 minutes later from home, yep, put it on reserve and rode it home....Happens to the best of us....!!!
 

Many years ago I had a Ninja 250. I was rushing around, making birthday preparations for a young lady, and as I was zipping along the bike started to cough. No problem, I reach down to switch the petcock...

And it was already on reserve.

Managed to get where I was going but that was a tense half-mile or so.

wrote:

Many years ago I had a Ninja 250. I was rushing around, making birthday preparations for a young lady, and as I was zipping along the bike started to cough. No problem, I reach down to switch the petcock...

And it was already on reserve.

Managed to get where I was going but that was a tense half-mile or so.
 

That's the worst.  did that on a road trip in my younger days...
coasted into a gas station on reserve, filled up and hopped right back on the road.

Never thought to switch it back, until 150 miles down the road, when it started to sputter again.
These were the days before cell phones.  was stuck sitting on the side of the road, middle of nowhere south dakota, until a random farmer came to my rescue.