TOPIC:

My kz900keeps fouling the plugs ever since i put the dyna s ignition and new 3. ohm coils on it.I,ve checked everything i can think of.When the battery is fully charged it puts out 14.60 volts at the battery while running.I'll take it for a test ride and it spits and sputters and gets worst and worst.The plugs are all black and sooty.I put the points plate back in it using the dyna coils and it does the same thing.When i check the battery after the test ride its putting out about 13.5 volts.I,ve changed the stator (and tested it w/ a meter)put in a new voltage/regulator, new battery.I,ve tested the leads from the stator while running it puts out 65 to 70 volts.I must ad that the wiring was bad on this bike when I got it, an I,ve replaced virtually every wire with new ones,one at a time.I removed the tank and ran the bike at night to see if I could see any arcing around the coils because i know there is an issue with primary wire being so close to the mounting bolt but there was none.I even removed that bolt on both coils and zip tied them so they would not move to eliminate that possibility but no difference.It ran pretty good w/the old coils on it so I'm gonna put them back on and try it and see how long if any thing shows up.Any ideas or input would be greatly appreciated because this is really becoming quite annoying THANKS

Sounds like the coils are not getting the proper operating voltage to work. Many people here have done a relay modification to their bike created by a fellow who goes by "wired George" at www.wgcarbs.com he runs a carb restoration business out of Texas and does wonderful things.

Go to his website,drop him a E-mail and I'm sure he can help,also Google wg relay modification.

Yeah I read about that .Its a great Idea but I also wired the coils and module directly to the battery with a toggle switch inline just to see if it made a difference and it didn't.Before i did that, I did check the voltage at the coils and it was a little over 11.5.Does the kz900 actually have enough alternator to run 3 ohm coils?

To determine if your bike needs the WG Coil Repowering Mod you need to determine the difference between the voltage across the battery (+) and battery (-) terminal and the voltage the coil (+) input and the battery (-) terminal.

In your example, the battery voltage was +14.6 or 13.5 while your coil input voltage was 11.5 which says that you are dropping a whopping 3.1 or 2.0 volts. With the direct wire and switch you describe installing you should have almost the same voltage at battery and coil input. If true, sounds like you have a bad connection or bad ground and it should be hot as hell were its bad.

Best of success.

PS
Could you add your year, model and location to your signature to get the best responses and it's considered friendly too.

If not already done, would assure correct valve clearances (and also perform compression test -- remembering to hold throttle wide open);

And would also assure correct floatbowl fuel level, using the clear tube test method.

Good Luck!

I just checked the alternator rotor to make sure it wasn't spinning on the crank and its not,it can't its on a keyway.It's a 77 kz900.I'm running it with the stock coils and points back on it.Its running better than it was but still missing badly.I'll check the carbs out and do a compression test.It has all brand new valves and guides and valve job and I adjusted the valves when I had the head off but ,if they are not right a compression test will tell.Thank you all for the responses

Just in case -- assure clean clear free-breathing air intake filter (not blocked with a shop rag or something ) and not over-oiled, if applicable.

And assure ignition timing is correct and that advancer unit is operating properly (watch it move back and forth with strobe type timing light while varying rpm).

Good Luck!

I'm guessing low compression, or maybe a bad coil.

checked valve clearance and all .002 to .004 which is within tolerance'checked compression and no cylinder less than 130 lbs. still have to check carbs. I'm still stumped though.I Thought for sure it might have been the valve clearance after a member mentioned that possibility.I had set the clearance when I had the head off but recently I installed new cam bearings and thought it might have changed the clearance but it really didnt ..............huh?