Carb question

I took out the 80 KZ1000 for a test ride again.The smoothbores was frozen on it so I swap on a KZ650 carb which I knew was good.The carb was set for pods and 4 into 1.I don`t know the jet sizes.It idles great,very responsive,but when I hit the 8g`s it`s dies like it`s lean,right before to get it on.My first thought was too small main jets.This bike also has a kerker 4 into 1.
Any suggestion?

The 650 carb is likely undersized for the 1000.

Guessing maybe a 24 being fitted instead of a 28.

Thinking that jetting won't compensate for smaller bore (carb throat) size, especially at higher rpm.

Good Luck!

Amen for that I will try to fix the original carb.

Ok, not sure I'm reading this correctly so I'll ask the stupid question of the day.... :blink:

In reference to your writing of "I swap on a KZ650 carb"...

This is singular and am assuming you meant the set of 4 but have to aske just the same... Am I understanding you swapped the SET (4) of carbs not just an individual carb.. Correct? :S

In either case, as Patton mentioned, would it start, maybe, would it run like crap, most likely due to jetting and head intake bores...

OMR

Yep,I was talking about the set.All four.

Thank the KZ Gods... :laugh: :laugh:

"My first thought was too small main jets." ...
@ 8000 rpm, Yup WOT, most probably main jets in this case.

Same time, this may be the point where the needle jet and main jet curves overlap.

Does it "die" then kick back in or just falls on it's face at that point?

You may want to try changing your needle jet clip position for a more richer operation if it isn't falling on it's face for the WOT range.

OMR

This is the original carb set,came with the bike.The first carb slider was stuck pretty much.This is the one.It does not seems that bad.I swapped with the next one,it`s a little sticky but will clean them up.

Hi!
Here is little update.I cleaned up the kz1000 carbs and put it back.It runs awesome but there is one thing still bugging me.It has a "floating" idle effect.When I revv it up it stays there for a bit and going back slowly.I think it`s either sync problem or airscrews out of specs.Any thought on this one?What should I check.And this is a smoothbore which I`m not familiar with.I worked on honda cb`s but this thing is different.

Thanks

Seems as though your slides are still sticking a little...

Reviewing static adjustments, when the throttle is opened and released, do the slides "Snap" spring back to start positions/heights in the bodies?

Possible vacuum leak but your gauges should provide some insight to that....

Those images depict some pretty nasty grunge and possible now that you have them running, some of that black crap residue is working it's way through the carbs.

You went from crap running, cleaned to awesome not with a little hang up... Good job!

Me personally speaking, before doing any other adjustments... take them off and clean again!

OMR

fandango wrote:

Hi!
Here is little update.I cleaned up the kz1000 carbs and put it back.It runs awesome but there is one thing still bugging me.It has a "floating" idle effect.When I revv it up it stays there for a bit and going back slowly.I think it`s either sync problem or airscrews out of specs.Any thought on this one?What should I check.And this is a smoothbore which I`m not familiar with.I worked on honda cb`s but this thing is different.

Thanks

I think it`s either sync problem or airscrews out of specs --- possibilities, or perhaps hanging throttle cable for whatever reason or a weak return spring.

But imo the culprit is more likely an air leak in the carb holder (old and cracked) or loose clamp at carb holder, or leak where carb holder attaches to engine.

Typical test is by spraying WD40, carb or brake cleaner, or propane gas (unlit--duh :lol:) around the carb holder area while engine is idling.
A noticeable difference in idle rpm usually indicates the unwanted intrusion of outside air into the fuel mix as it enters the intake tract on its way to the combustion chamber.

Good Luck!

You went from crap running, cleaned to awesome not with a little hang up... Good job!

OMR!

I took off and back three times already,that is my magic number.I always find a little hole somewhere.The final procedure was boiling the jets and the whole carb.

Intake manifolds in good shape (not hard/cracked etc...)?
Even with new manifolds, I put a little vacuum grease on the outside sleeves to insure no leaks....

When this hang up occurs, with gauges in place, are all 4 carbs acting up or just one?

As Patton mentioned, weak spring, cable hanging up...

Open the throttle, while reviewing the cable tensioner/springs, release the the throttle and let it snap back to idle... Are you seeing the hang up in the mechanical spring adjuster plate area or is it truly in the carbs themselves...

I don't know your carbs so just guessing but if all 4 are acting up simultaneously then has to be something in common they all work off of such as choke assemblies, starter circuits etc...

OMR