Carb Sync instructions 79 kz1000

That looks like a pretty good deal. Especially with the extra main jets.

Is this the only way? :lol: :silly:

Who wants to give me $765.95 for my 29 Smoothies????? LOL

Can someone please explain (or link me to an explanation) of the parameters involved in carb syncing and how they interact? So compression plays a role because it creates the vacuum. But does it involve fuel flow at all? Or how well the carb is performing? For example if three cylinders be firing and one not, but all cyls have great compression, could the sync be even across all cyls?

richrand wrote: Can someone please explain (or link me to an explanation) of the parameters involved in carb syncing and how they interact? So compression plays a role because it creates the vacuum. But does it involve fuel flow at all? Or how well the carb is performing? For example if three cylinders be firing and one not, but all cyls have great compression, could the sync be even across all cyls?

Very doubtful. When a cylinder fires the exhaust pulse creates a scavenging effect which in turn affects the intake cycle. So the intake vacuum on a cylinder that is not firing would not be identical to that of a cylinder that is firing and the failure of a cylinder to fire may also actually affect the intake of cylinder(s) that is/are firing because of uneven scavenging. If you were to synch all carbs while one cylinder is not firing, once you fix the problem and that cylinder is firing you should synch again. Best bet is not to bother with a fine dynamic synch until all cylinders are firing properly. Have you identified the problem that prevents one cylinder from firing? Ed

Thanks, Ed. I have not. My number 1 isn't firing properly. Compression is 145 cold. Carbs have been gone through twice. It seems to run better when the carbs are set to super rich -- like 4 turns out. Then if I roll back the mix on #1 it will start to stumble when it gets near closed. So it's doing something. I've done the ignition-circuit mod, but I'm pretty sure the stock coils and wires are fading and spark isn't optimal. Nevertheless, when I switch the #1 and #4 leads, the #1 cyl still doesn't fire right. Like I said, a super rich setting seems to make it run better.

Ive got pods and a 4/1 (baffled), mains are 117.5 and pilots are 17.5. I don't know the needle position. Float level is set right. Any ideas??

Here are some things you may want to check if you haven’t already:

Valves adjusted within spec
No air leaks at #1 (or other) carb holders
Pod on #1 not blocking orifices on intake mouth
When you swapped #1 and #4 spark plug leads, did you also swap spark plug? Could #1 plug be bad?
Does #1 stumble at all RPM or only at idle?

Thanks, Ed. I did swap the plugs. I'm going to pull the carbs and valve cover tomorrow and check everything again, including cam timing. I'll disassemble the carbs again and check the needles too. Manifolds are sealed, but I agree that this seems like the #1 is not sealing tight somewhere.

I am curious what you find your problem to be, because I have the same problem. I just did a ground up rebuild of my 76 KZ900 LTD. Here are the mods:

-new 1075 kit (compression tested good on all cylinders, about 140)
-new PSP 3X cams (degreed to 106)
-new Mikuni RS34 Flatslide carbs with 125 main, needle jet on P4
-new carb manifolds
-new pod air filters
-old Dyna S 3 ohm coils and ignition timed according to the Dyna procedure

Cylinders 2-4 are running good, slightly on the lean side but ok (based on reading the plugs), but cylinder 1 plug is black and wet. My spark tester shows there is spark on #1 and it jumps the gap on the tester fine. Also my laser temp reader shows the exhaust header on 1 only gets to about 160 degrees, and 2-4 all get up to about 600 after a few minutes of idling. I've swapped plugs, plug wires, and cylinders 1 and 4 on the coil, but the problem always happens on cylinder 1. I don't know where to go from here. Is this a carb issue, cam timing, ignition timing? I'd greatly appreciate any input.

Brady

If the problem is only on 1 cylinder I don't think it could be a cam or ignition timing problem. Ed

650ed wrote: If the problem is only on 1 cylinder I don't think it could be a cam or ignition timing problem. Ed

That's what I was thinking too. Seems odd to already have an issue with brand new carbs though. I have not synchronized them, so I was thinking of doing that next. Doesn't seem like out of sync would be the problem though.

Z1-Ent Tech line suggested I swap the 1/4 and 2/3 coils to see if the problem follows the coils/wires. Its a great idea that I'd do if the 2/3 wires were long enough -- which they aren't on my machine.

richrand wrote: Z1-Ent Tech line suggested I swap the 1/4 and 2/3 coils to see if the problem follows the coils/wires. Its a great idea that I'd do if the 2/3 wires were long enough -- which they aren't on my machine.

Since you already swapped the #1 and #4 leads and plugs and the problem did not change I don't really see what swapping coils could prove. Since the coil, leads, caps, and plugs for both #1 and #4 fire cylinder #4 fine but will not fire cylinder #1, the ignition system would appear to be working ok. Ed