Poppity poppity poppity

Getting old listening to this thing. Ok, KZ guys, I have just acquired a new ride that has me puzzled. Although I haven't had time to dive in and start tuning, I have a general question for an area to concentrate on to find this popping I have in my '78 KZ1000.
Starting off, the engine was built years ago with factory '78 KZ pistons using a 903 jug bored for factory clearance on the 1015 pistons. New Kawi rings, cam chain, tensioner, rollers and guides. Recent valve job with new seals and valve clearance set. I did not build this engine and have not done a compression check yet. I do not know what the valves are set at now. I will check all of this when I dive in to tune this bike.
The bike has a Bassani Superbike pipe and 29mm smoothbores w/K&N pods. Running 120 mains and air screws at 1 turn out. I have been turning on the screws and found that 1 1/2 turns out creates more popping through the exhaust. 1 turn out seems to run best. I haven't had the carbs off to check pilots, I'm hoping there are 17.5s in them. The sync is also probably off on this bike because of moderate vibes and seems to labor to idle smoothly. Will check/set float level when I pull them off to clean and service.
The bike also has a full Dyna S ignition and Green coils. The PO said something about the coils weren't wired to the Dyna directions, and I haven't had the tank off to look at what he was referring to.
This is basically the exact same set up I had on my 1980 Z1-r back in the day, except for the pipe.
I don't remember my Z1-R ever having a popping noise in the exhaust and it idled way smoother than this bike.
The bike runs way to good for the carbs to be stopped up, but I know they will need a thorough cleaning when I pull them off.
Outside of doing a good carb cleaning and syncing, valve lash setting, and fresh plugs, what else could be causing this popping at low speeds and idling? Ignition related maybe?
I do get a spitback every now and then through a carb. So I will re-seal my manifolds when the carbs come off.
Sorry for the long post, and I most likely will "tune" the popping out of it with a full tune up, but I was looking for some good advice from the collective that may have stumbled onto this problem themselves.
It has been a long time since I had a KZ running. Feels good riding one again and I want it running like I know it can. ThanKZ.

I would say that it is lean with pods 4 into1 pipe and stock jetting. May also have leaking manifolds spray around the carbs with carb cleaner or wd40 while at idle to see if it changes the idle speed
good luck

Every Bassani pipe I've seen on a Kawasaki has a large collector diameter. That can influence the low speed carburetion.

Aslo, I've seen 29's Mic's like as little as 1/4 turn on the air screws. Some don'r respond progressively to air screw adjustments either. You may have only one cylinder causing the popping. If it's the carburetors and they like 1 turn out, try backing them to 3/4 turn.

LarryC wrote: Every Bassani pipe I've seen on a Kawasaki has a large collector diameter. That can influence the low speed carburetion.

Aslo, I've seen 29's Mic's like as little as 1/4 turn on the air screws. Some don'r respond progressively to air screw adjustments either. You may have only one cylinder causing the popping. If it's the carburetors and they like 1 turn out, try backing them to 3/4 turn.

I agree on that part being the main difference than my set up on the Z1-R. The Bassani collector/mid pipe is HUGE compared to the MAC I have on the Z1-R.
Larry, I did go in to 3/4 and to 1/2 turn on the air screw. Didn't seem to like going in. The last thing I did was pull each one out and spray carb cleaner through the air circuit. I'm going to go in a 1/4 turn at a time again and see if that helped.
Could the coils being wired incorrectly be giving me some ignition problems? Seems like the PO said they were inverted compared to the illustration in the instructions. I haven't pulled the tank yet to give it a look.

I would check those carb holders for leaks. It will only take 5 minutes and could be contributing to the problem. Temporarily idle the engine down as low as it will go and still run; then spray carb cleaner aroud the carb holder/cylinder head joints and also around the carb/carb holder joints. If they leak you will see the idle change. When mine were leaking the engine stopped running as soon as I sprayed. Ed

I had the same problem after adding 28mm carbs to my KZ810. I was able to get it to a reasonable level by richening up the fuel/air screw and closely read my plugs. I also put in a slightly hotter plug, and that had the biggest influence.

I will note that I was only comfortable adding the hotter plug after I had installed an oil cooler.

Yorke

1 other thing to check is the exhausts gasket seals. take off the exhaust and examine the gaskets. look carefully to see if any black soot is escaping past the gaskets. some headers (due to there design)actually need thicker , or double gaskets to seal properly. Z1E sells thicker 1's.

I started a tune up on the KZee this evening. All valves were between .0035-.004 except for one intake. It was around .0015 or less, opened it up to .0035.
All intake manifolds had cracks at the head mating surface. Three Bond fix till I get new ones.
Pulled carbs down, cleaned and set floats @ 23mm, I don't have a fuel height gauge for the 17mm hex plug yet. Carbs have 17.5 pilots
Had two slides moving vertical from linkage wear. Stretched the linkage spring a tad and tightened that up. Sync was out, set mechanical sync. Will put it back together tomorrow and see how it runs.
I had a feeling the intakes were going to be cracked.

ThanKZ for the input.

If its popping when you decel you might wanna plug the exhaust emmission ports, just a thought.

Powerstroke_fan wrote: If its popping when you decel you might wanna plug the exhaust emmission ports, just a thought.

N/A x 2

Got the carbs back on and fired it up this morning. After some tuning on the air screws I'd say 90% of the popping is gone. Every now and then a pop at idle.

Two of the carbs had float heights set on 20-20.5mm from gasket surface when I went in them. Set them all on 23mm.

I really need to set the fuel level in the carbs with a gauge to get it perfect, but they're closer now. I can tell it did lean the idle out a bit, as I am at 3/4 turn on my air screws now.

The bike is a lot crisper sounding and feels responsive just blipping the throttle. Raining and tornado watch today, no test ride.
Would I be better off going to #20 pilots to get the air screws opened back up to 1 1/2 turns out.
Idle speed wonders a bit. Not super steady yet.
Here is what's in the carbs now:
1.5 slide cutaways
17.5 pilots
120 mains
float height 23mm
air screw 3/4 turn out
K&N pods
Bassani 4-1 superbike pipe
Dyna S with green coils
valve lash .0035-.004 on all valves
mechanical carb syn, no running sync done yet

EDIT: Just looking at the Sudco catalog, it looks like I should have #25 pilots in these carbs.

If not already done, would verify fuel level using the clear tube test.

Good Fortune!