Daisy has lost her spark!

[gijoe1313]

Heheh thanks Smudge, Donor and I will be tackling it again tomorrow - we've got some ideas and will check them out! Yep, RZ's are luvverly simple bikes - I think she may be sulking due to my dalliances on the little ol'Hornet for longer trips!

Have multimeter, will have fun!

[Ixion]

Here is some info about testing RZ ignition. I don't vouch for it but on a quick read through it seems sane

CDI Troubleshooting
CDI theory:
The CDI ignition takes a pulsed current generated by the low or high-speed charge coil (depending on engine RPM) and charges a capacitor. This stored charge is then discharged into the primary winding of the ignition coil causing the plugs to spark (both at once). The timing of this discharge to the coil is triggered by the arrival of a small electrical pulse generated by the pickup coil and electronically delayed to occur at the proper time by circuits internal to the CDI module. The ignition, engine run and side stand control unit provide a circuit to ground to "kill" the ignition. There is an old saying "garbage in equals garbage out" If any of these signals are missing or a short circuit to ground occurs in the "kill" circuit, the CDI will be unable to function properly.

Install a set of NEW plugs. The secondary winding of the ignition coil is attached to both plugs. In order to complete the circuit the current must flow down one plug wire to the plug, jump the gap, go thru the engine cylinder head to the other plug, jump that gap then go back up the wire to the coil. If you interrupt this circuit, neither plug will fire. If you do experience one plug sparking without the other, the circuit is being completed another way, perhaps through the plug wire insulation to the frame or perhaps internal to the ignition coil to the metal core which is bolted to the frame.

The RZ electrical connectors can corrode pretty bad. The engine vibration helps to maintain good contact but a bike that has set for a while can develop electrical "ghosts" quite easily. So lets start by separating, inspecting and re connecting all the electrical connections associated with the ignition system. When that is completed take the following readings. The following readings can be taken using the standard test leads that come with most digital volt ohmmeters. The RZ electrical system is connected together with molded nylon "molex" or "spaid" connectors. All the initial readings are taken with the circuit under their normal electrical load. This means that all the connectors are connected and you take the reading by sliding the test probe tip into the molded connector alongside the proper colored wire until it makes contact with the metal portion of the electrical connector. You need a digital voltmeter as the delay in the needle reaction of an analog meter might miss some of these very small signals
1. On the CDI bundle find the connector with the black wire with a white stripe running along it. Put the red test lead in along side this wire. Hold the black lead against the bare metal of a head bolt. Set the meter to read resistance. With the kickstand up, engine in neutral, the kill switch set to run and the ignition key to on you should see greater than 30K OHMS of resistance. If you turn off the key or kill switch the resistance should decrease to near 0.

ALL OF THE FOLLOWING READINGS ARE TAKEN DURING 5 RAPID KICKS! The object is to keep the engine rotating long enough for the digital meter to sample the signal and display a reading. This is easiest with the spark plugs removed, the plug wires connected to the plugs and the plug body connected to ground on the engine case to complete the circuit. What also works well is to tape the metal bodies of 2 spark plugs together, with the insulators pointing away from each other. Attach the spark plug wires to these and this will also complete the coil secondary circuit.

2. On the end of the CDI wiring harness you will find a 3-wire connector that has a brown, red and green wire. Slide your black probe in beside the brown wire and the red probe in beside the green wire. This is your low speed winding. Set the meter to read AC volts, turn on the ignition and kick the machine over 5 times quickly. You should see, while kicking, a reading of 25 Volts AC.
3. Now move the red test lead to the red wire (measuring brown to red) this is the high speed winding kick over the machine with the ignition on and you should see 4.5 Volts AC.
4. On the CDI bundle there is a 2-wire connector with a white with red stripe wire and a white with green stripe wire. This is your pickup coil connector. Slide your test leads in beside these 2 wires. When you kick the starter rapidly you should see 0.3 Volts AC
5. On the CDI bundle there is a 2-wire connector with an orange wire and a black wire. Slide the meter probes in beside these wires. This is the CDI output to the ignition coil primary winding.
When the starter is kicked rapidly, you should see 0.4 Volts AC.
If any of these voltages are missing one of 2 things is happening. Either the source device is not generating the signal or the destination device is shorted and the signal is being loaded down. If one of the signals is missing, separate the electrical connector for that signal (electrically unload it) and connect your meter to the source side and repeat the test. Here are the unloaded readings for the above listed signals
2. Low speed charge coil 50 Volts AC unloaded
3. High speed charge coil 4.5 Volts AC unloaded
4. Pickup coil 0.3 Volts AC unloaded
5. CDI output 24 Volts AC unloaded
In the case of signals 2,3 and 4 if the loaded test is bad and the unloaded test is good do a resistance test of the source device. The low speed coil (test 2) should read 225 ohms (or 133 ohms depending on engine type). The high-speed coil (test 3) should read 5.3 ohms and the pickup coil (test 4) should read 115 ohms. If the resistance check is good the CDI is most likely at fault.
In case the signal 5 load test is bad and the unloaded test is good, measure the resistance of the ignition coil primary winding. The primary winding resistance is around 0.33 ohms. If it is OK then the CDI is most likely at fault.
If all the above readings are good then check the secondary winding of the ignition coil, the measurement from one plug cap to the other should be about 23K ohms. The plug caps themselves "screw" (twist counterclockwise) off of the plug wires each plug cap should read about 10K ohm when measured by itself. The coil and plug wires alone should read 3.5K ohms. It is possible for the coil secondary to be breaking down under high voltage but measure just fine with the ohmmeter. If you are getting the proper signal on the black and orange wire to the coil with no spark out into NEW plugs, then the coil is probably at fault. I had this happen intermittently for about a year, I finally found it by connecting up a meter to the black and orange wires and taping it to the tank where I could see it. The next time the bike quit, while I was coasting in gear the input voltage was still there with no spark out, Good in, garbage out. told me it was the coil. One final word of caution. DO NOT ATTEMPT TO MEASURE THE OUTPUT SPARK VOLTAGE FROM THE IGNITION COIL! IT WILL DESTROY THE METER!

[Ixion]

The RZ is a pretty simple bike, no funny safety switches or nothing. ,,,.

Would that they had never abandoned such elegant simplicity. What was wrong with the old system? Wire from the mag to kill switch. Wire from battery to earth. Wire from battery to regulator, and regulator to earth. Wire from battery to headlamp switch, thence to tail lamp and dipswitch , thence to headlamp. Complete wiring circuit there. See, simple.

But the wiring diagram from the RZ350 shows a sidestand switch and a neutral switch both going to a control box which earths the CDI (parallels the kill switch).

[xwhatsit]

Alright, well we had a frustrating night.

Could not get any sort of spark from the spark plug. Tested everything forward from the pulser, it seems to all be working fine.

What we ended up doing, was checking what voltage we were getting going in to the coil when the bike was kicked over. There was certainly a voltage going into the coil, maximum 20V was going in. However we weren't getting anything useful coming out the other end. Is 20V enough to produce any signs of life in the coil? Or do we need to pump more voltage in, and the CDI/something else is faulty and too weak?

[Conquiztador]

Alright, well we had a frustrating night.

Could not get any sort of spark from the spark plug. Tested everything forward from the pulser, it seems to all be working fine.

What we ended up doing, was checking what voltage we were getting going in to the coil when the bike was kicked over. There was certainly a voltage going into the coil, maximum 20V was going in. However we weren't getting anything useful coming out the other end. Is 20V enough to produce any signs of life in the coil? Or do we need to pump more voltage in, and the CDI/something else is faulty and too weak?

OK, think your self a bike with points. You turn on the ignition, then you open and close the points manually (no turning motor over) and you get a spark. There is only 12 V in the system from the battery.

In your case you will not be able to measure the pulse from the CDI with a multimeter. You will need a oscilloscope or similar.

Don't know your bike but most (if not all) 2 stroke ones that have a magneto that have 2 or 3 coils in there. One for charging the battery, one for the lights and one for the ignition. Or if 2 coils then one for charging and lights and other for ignition. If you have spark problems you can forget about the charging coil and the lights coil. Focus on the one that produces the spark. That one will feed the CDI that then does it's stuff and feeds the coil. The CDI needs to know when to produce the spark and so you should have some sort of sensor. Normally a small one on outside of magneto or at times inside.

If all wiring is ok, magneto is working and no kill switch is causing the problem then my suggestion is to replace CDI.

Good Luck.

[Ixion]

CDI output to coil, unloaded should be 24volts. Dropping to 0.4 V loaded. So 20V is about right.

Are you sure you are getting a pulse signal? Like the man said it will be very hard to pick that up on a cheap multimeter.

Check the coil.
"measure the resistance of the ignition coil primary winding. The primary winding resistance is around 0.33 ohms. If it is OK then the CDI is most likely at fault.
If all the above readings are good then check the secondary winding of the ignition coil, the measurement from one plug cap to the other should be about 23K ohms. The plug caps themselves "screw" (twist counterclockwise) off of the plug wires each plug cap should read about 10K ohm when measured by itself. The coil and plug wires alone should read 3.5K ohms"

[Lteejay]

Hows your baby hornet man? Have you breathed life back into her? Hope you get her running soon

[xwhatsit]

The coil checked out fine, the values were `in the ballpark' -- not ideal, but when you're talking about 0.33 ohms the fact that it is a cheap multimeter comes to mind again.

So if 18-20V is going into the coil, and there's no spark, then there's a lack of pulse? It wasn't 20V all the time, only when we spun the flywheel. But you're saying that that signal is not going on and off?

We checked the pickup coil, it was fine.

We were going to change the CDI, but decided not to last night; I think Justin's going to try that today some time.

It's great having all these spare parts to chop and change, you just have to make sure they're working first.

[gijoe1313]

Okay, thinking is kill switch the prob ... now, should power be measurable at the kill switch end when ignition is on?

Pulled switch apart, contacts look fine ....

Ideas?

[Ixion]

The kill switch earths the CDI unit. So, with the ignition key on, not turning motor etc, you should NOT have continuity to earth on the wire that runs from the CDI to the kill switch. It's a black and white wire. Trace the wire back from the kill switch to the CDI , disconnect it from the CDI and (with the kill switch assembled, in run position, ignition on) you should NOT have continuity to earth. If you do, somethings shorted.

It could be your YPVS unit is stuffed That can short the CDI . Not very likely though.

[Ixion]

Two thooghts. One is that twice I have had problems with Yamaha ignition switches failing internally. So that although they appeared to function normally, in fact they weren't "turning on" .In fact, it's a turn 'off'. When you turn the key to the on position, it breaks the circuit which is earthing the CDI. The switch uses mutliple sets of contacts so other ignition controlled stuff may work OK

The other is that a coil may measure up on the meter but still not output a spark, if there is an internal short circuit - ie the spark IS happening but it's happening inside the coil.

[avgas]

OK,
first things first - what have you done since the bike last ran?
If you havent done anything, check the following:
a) Kill switch on the RZ's are prone to all sorts of crap, check it is atleast doing a contact. My 250 used to take 5 flicks to engage properly.
b) Check the loom is not making a dead short to the frame.......this does all sorts of bad.
c) how crap/old is the fuel? Older than 2 weeks chuck it.
d) is there oil in places there shouldnt.....plugs etc?
e) How crap is your plug?
f) Is the CDI plug in properly?
Sorry for stating the obvious here, but if you get all shitty and go out to prove me wrong, you make look at this from another point of veiw.
I have a horrible habit of saying "YES YES YES" then when i am told to prove it.....i find the error.
I take it she has been parked inside since she was last ridden?

[Conquiztador]

Okay, thinking is kill switch the prob ... now, should power be measurable at the kill switch end when ignition is on?

Pulled switch apart, contacts look fine ....

Ideas?

Simple test: Leave wire to kill switch disconnected and your kill switch will do no harm. Stll no spark = kill switch is not the problem.