TOPIC:

boogiepicker wrote:

Does anybody here have a good running kz900 streetbike with dyna 3 ohm coils with no problems?I cant get mine to run right with the 3 ohm coils, tried everyhing u name it I've tried it

tried everyhing u name it I've tried it--

Which particular diagnostic tests have already been performed (such as visual inspection of spark quality, resistance measurements, etc.)?

From reviewing your earlier posted topics, compression figures and valve clearances seem okay.

If there's a properly timed good quality spark, the ignition system is probably also okay.

Perhaps there's a problem with the 29 smoothbores, such as delivering an excessively rich fuel mixture?

For instance, the pilot circuit air intake jet is tiny and difficult to clean. And the pilot circuit air passage might need better cleaning.

Am running Z1 with green Dyna 3-ohm coils, Dyna-S ignition, Dyna solid core plug wires, and Mikuni 29 smoothbore carbs (and "Pops Yoshimira" head). Perfect performance throughout the power band from consistent, slow steady idle to wot, all with nice tan plug readings (4/1 VH with K&N in stock airbox).

Same ignition setup on KZ900 with oem 26mm Mikuni carbs and Kerker 4/1 with K&N in stock airbox. Wisco 1015 kitted with no performance issues whatever (but won't stay with the Z1 ).

Am pleased and well-satisfied with the Dyna equipment.

If not already done, would also assure correct floatbowl fuel levels by using the clear plastic tube test. As known, too high fuel level often results in excessively rich mixture even with otherwise perfect carb.

And just for kicks, would replace all four plugs with brand new NGKB8ES.

Good Luck!

I just swapped out the coils from my cb 750 which also has dyna coils but they are 5 ohm still runs like crap ,sounds like a popcorn popper spits and sputters ,I swapped out the igniter box same thing,carburetors 29mm smoothbores completely dissasembled cleaned, new needles in middle position,new inlet needles and seats,120 main jets 25 pilots individual filters ,reset floats,have a relay from battery powering the coils,checked all grounds added some grounds,new combination regulator /rectifier,swapped out the stator,even though i dont think it was bad,adjusted valves nothing tighter than .004",good compression,kz900 motor w/kz1000 cylinders and cams.The only thing I havent swapped out is the dyna pickup plate and rotor.Funny thing is It did run decent with the old coils and points?

If not already done, would visually inspect spark quality (look for fat blue spark) by removing plugs, hold base against engine while spinning engine over with ignition switched ON and kill switch in RUN position.

Good Luck!

boogiepicker wrote:

... swapped out the igniter box....

igniter box - - -

Something to verify....

Not sure what bike you have so just some thoughts...
Via Z1 Enterprises:
For some Kawasaki bikes with a resistor in the circuit (i.e. KZ1000's in the late 70's and early 80's), the 3 ohm coil is the best choice - just remove the ballast resistor from the circuit.

There's also a possibility in the following "GREEN Coils" where there are two different versions of Green coils...

Did you order Dyna Single Output 3.0 Ohm Coils (pair) DC3-1. Used on Twin cylinder motorcycles with 2 single coils, or Triples with 3 single coils, or used on 4 cylinder motorcycles using a Dyna 4000 setup.

or the preferred Dyna S series ignition....

Dyna Dual Output 3.0 Ohm Coils (pair) DC1-1
DYDC1-1. 3 ohm green coils. Replacement for factory coils. Matched to the Dyna-S Electronic Ignitions.

For testing only, swap to original coils (~4 ohms) or keep new coils and install original contact breaker assembly.
Any difference...

Not sure I'd use the CB750 coils for unknown what the resistance values are with these coils.

Also, are you running 7mm (preferred) or 8mm plug wires...
Speaking of plugs, what's their condition...


Just some thoughts...

OMR

These are the dual output green 3-ohm Dyna coils from Z1E.

Green Dyna 3-ohm dual output coil from Z1E

Just to make sure I wasn't speak out of my ass.... Got out the KZ900 Factory Service Manual...

Not trying to insult, just making sure...

Coil Installations:
Black to contact breaker Black.
Green to contact breaker Green.
Brown to yellow/red wire.
The high tension wires are labeled with the spark plug numbers.

OEM resistance measurements.
The primary winding resistance between the red/yellow conductor and the green or black lead should measure between 3.2 to 4.2 ohms.

The secondary winding resistance between the two spark plug conductors is about 30K ohms.

There should be no continuity (infinite) between the red/yellow conductors or the plug and the coil conductors.

Since the DC1-1 3 ohm green coils are a direct replacement for factory coils, these should measure close to the same.

Let us all know the outcome of your findings for our learning and knowledge as well...

Good luck,

OMR

Patton,
"These are the dual output green 3-ohm Dyna coils from Z1E.
Green Dyna 3-ohm dual output coil from Z1E"..

I realize that but there's two different versions of GREEN coils available. Just making sure he got the correct ones.
Not sure why it would make a difference but just in case...

OMR

I just raised the float levels ,changed the pilots from 25 to 20's no difference the plugs are sootie but they were sootie before I'm absoulutely baffled

I believe the difference in the coils you are talking about one is a single tower(one plug in) the other is a duel tower(2 plug ins)Ive got the right ones

Some random thoughts.

Fuel
Sputtering...popcorn -- Possibly water in fuel. Could detach fuel line from petcock and drain carbs. Then test run using an alternate fuel source (with known good fuel).

Air Filter
Dirty or blocked air filter?

Float Level
Correct float level verified by clear plastic tube test -- NOT the upside-down-on-the-bench measurement method.

Battery
Battery fully charged and holding charge with specific gravity tested to specs.
Good solid connection where battery negative cable attaches to engine or frame.

What igniter box???
Still puzzled by having reportedly "swapped out the igniter box." The oem KZ900 points ignition does not have an igniter box. Replacing points ignition with Dyna-S electronic ignition does not involve an igniter box. Thinking any igniter box implant into the Dyna-S system was ill-advised.

Wiring
To confirm -- the black wire from left Dyna-S module signals left coil which fires outside plugs. Green wire from right Dyna-S module signals right coil which fires inside plugs.

Modules
Are the module pick-up areas and rotor magnet clean?

Is the rotor magnet adjacent to the left module when the 1/4 F mark aligns with the permanent fixed timing mark on the engine case? This interrupts the left coil's primary terminal ground which causes it to send high tension voltage through the secondary loop to fire the outside plugs.

Yes, it is possible for a Dyna-S module to go bad. Am thinking detailed testing procedures are found on Dyna's website. Perhaps it's time for a test with the old points plate re-installed, but would first check out the other possibilities.

Review of Basics
As known -- the three essentials for proper combustion are:
(1) Compression (looks okay);
(2) Good, properly timed spark (no report yet as to visual observation of spark quality);
(3) Correct fuel mixture from carbs, with ample good clean fuel supply to carbs.

What Now?
Likely spinning wheels here until assured of good quality spark evidenced by visual observation.

Good Luck!

1. not the fuel
2.not air filters using pods
3.float level I'm adjusting them now AGAIN They are 29 mm smoothbores I read on here wiredgeorge said 23mm from the carb body w/no gasket I tied that.in that setting the floats are just about touching the inside top of the carbs it didnt make any difference anyway so now I made an adapter to screw in the bottom(17mm drain plug) and im setting like the book says w/clear tube".180 from carb body
4.Its a new battery but Since I dont know what the hell the problem is I rechecked it was down a little on water topped off w/distilled water all cells test good.Made up a new positive cable
5.ok maybe its not called an "igniter box" its the Dyna "s" electronic module its not that because I swapped it with a known good one from my other bike
6.Yes the modules are clean and the rotor is in right if you put it in wrong(180 off)it will just fire the other set of cylinders on the wrong stroke
7.I tried a new plug laid it on a ground,turned it over and it looked pretty good Now I have three sets of plugs all sooted up and the spark dont look so good
This is driving me mad if you ask me I would say its just not getting enough fire but WHY.............I do appreciate your help thanks you want a challeng well here it is