Weak Spark -81 Gpz 1100

My bike has developed what I think is too weak spark and I wanted to confirm what the spark should look like since it has been a while ago I checked it.
The bike ran poorly last time and stopped and would run intermittently.

I have since charged battery, replaced both coils, 4 sparkplugs, measured resitance on coils per manual (at spec),verified pick up coils ok tec. The sparks I think look weak, they are blueish but seem to jump around a lot and pretty thin...
Not sure if the IC ignitor unit can give weak spark or if it only fails completely - no spark?
I have also cleaned and made sure there is good connectivity at plug wires and plug caps.
Also checked opened and cleaned wire connections for coils and pick up coils. (Pick up coils check out OK too).

Anyone with ideas for other trouble shoot and feedback on how strong the spark should be?

Bike is stock -81 1100 Gpz (except Vance Hines 4-1) 20K miles MINT.

Check what the voltage is at the coils. It should be about the same as the voltage across the battery terminals. If the voltage is low go to WiredGeorge's website and look up his coil power rewire. If voltage is the problem its a guarantee this simple modification will cure it.


Oops, forgot the link : www.wgcarbs.com

Delete please...ratchen fratsit

IMHO, Bob is on the money. All these old bikes need this WG Coil Re-powering mod desperately. We will never know how may were put on the scrap heap and could have been save by this simple and inexpensive modification.

Best of success.

The "wired George" relay modification will make your bike a whole lot easier to start. I've read here about one kick starts. One guy had to lower his engine revs by 500 rpm due to increased combustion efficiency. The spark after the mod will be a hot,fat blue spark.

Thanks Bob and all for the idea. It looks like I may have to give that set up a try.

But I must have some serious wiring issue I need to find first...

I just did some more measuring:
At Battery = 13.3 Volts
At left Coil ingoing two leads (disconnected from coil) 9 Volts, while cranking 7 Volts.
At Right Coil ingoing two leads (disconnected from coil) 0.25 Volts!!!, while cranking 1 Volt...
Can't even understand how I can get any spark with these readings, but I do - weak no less...

:S

Just my two cents worth...

Do the WG Coil Re-powering mod. Your current symptoms could be caused by bad contacts, bad Kill switch, etc (as they were on my bike). If you bypass all of these with the mod then the voltages will be right on the coils, your bike will run well and you will be good-to-go.

If you insist on proving this out then try running a 12 AWG Red wire with a cheap inline 5 Amp fuse from the Battery (+) Positive lead directly to the (+) side of both Coils. The voltage on the (+) side of the Coils should now be only very slightly lower that at the Battery (+) Positive. If not, then the meter is wrong or you are not putting the (-) Negative (Black) meter lead directly on the Battery (-) terminal during all tests. If the voltage dips when one or the other of the Coils is fired (ground on the Black or Green leads), then that indicates a low battery charge or weak battery.

If you continue to have symptoms check the big Black ground wire from the Battery (-) terminal to Engine ground lug.

Best of success!

PS
DISCONNECT the test Red wire when the test is over... if not, you may kill the battery, melt the cois or both.
Bill

Whoa nellie! How the heck are you getting 13VDC at idle? Get yourself another multimeter and recheck. You should essentially get 12VDC at idle as the battery isn't charging... you are measuring battery voltage. If your battery voltage with the bike at rest measures 13VDC, there is something wrong with the battery. You may want to check your charging system as well such as check battery voltage at IDLE and then at 4K rpm. Do this before doing any rewiring I think.

Acutally it is not running / idling when tested only igntion on.

The 13V+ reading was just after a fresh batt charge.

Re-did test now:

At Battery: 12.3 Volts

At both coils in leads : 10.2 V

So better readings than the other day, but I am still loosing 2 Volts from Battery to Coils.

Not sure if the re-wiring would work without modifications for my bike. I have a Gpz which has ECU and IC Ignitor box that powers the coils, it would have to be included.

I will doulble check battery ground to engine and then maybe get a used IC Ignitor box (21119-1030) since there is no extensive test for that one.

Thanks

Apex2, as you have guessed a 2.1 Volt is huge. You are on the right track.

Sounds as if your bike is still a candidate for the WG Coil Re-powering mod... but that's been said to death.

Since I don't have your model bike or type of ignition, I will stand down now and let better informed members jump in.

Best of success.

Kawasaki Relay Coil Question

(Taken from WG’s information and his website www.wgcarbs.com )

The bike you own has an electronic ignition. There are pickup coils (two) mounted around the end of the crank shaft and mechanical ignition advance under your right hand points cover. The black and green wires originate at the pickup coils (the black comes from the 1/4 pickup coil and the green from the 2/3). They go into the gizmo you called a heat sink. It is actually an igniter box. The igniter box tells the coils when to fire and these signals are carried to the coils via BLACK and GREEN wires. The black wire is going to your 1/4 coil and the GREEN wire is going to your 2/3 coil. THESE ARE NOT POWER WIRES AND YOU DON'T MUCK WITH THEM IN THE COIL POWER MOD.

OK... the OTHER wire connected to each of your coils is a yellow/red wire. These wires are the powering wires. The power on them starts life back at the fuse box area and runs along your wiring harness. It goes through the igntion and then the kill switches and back along the wiring harness and to a connector over your valve cover. The connector is a one into two type female connector.

Over your valve cover, if you trace the yellow/red wires BACK from the coils, you will find that they connect into the one into two type female connector. You need to pull them lose and use one of them to TRIGGER your automotive type relay. Out of the relay, you will have power and this power can be split to feed the coils and connect to the red wire on the igniter box (the heat sink looking thing). It is a three way split... I don't recall how the red wire is connected to power but you can also leave it as is if you like. I have only done the conversion to a Kaw electronic ignition once so my memory is foggy as to how the red wire connects on your igniter but it is a power wire so either leave it as is or connect it to the split powering wires that will feed your coils.

Thanks for clarifying the coil wiring, makes sense.
I'll check some more on the different parts of that.
I did already test the pick up coils OK and also took apart the kill switch and cleaned it.
I may open up the igntion switch to clean and try and trace all parts of the coil's power wiring...
I may still go for the conversion, your clarification helps.
I'll post once I have updates.