[Dave1]

Hello guys

So as some of you may know. My bike is showing no spark, even with two new spark plugs, one a normal spark plug the other an Iridium. No spark at all. I tried the kill swith in both positions, no change. My bike has the Eureka Electronic ignition fitted, which retains the mechanical advance/retard mechanism.

My bike is an Iron Barrel 500cc 2004. It has a PVL coil fitted by the previous owner. The engine turns over fine, it has an electric start.

I am not a electrical wizz kid, so I will need things explained clearly and if I make mistakes then sorry.

From my limited experience, I though the next thing to check was the HT lead and coil. So the primary reading was 3.9 ohms with the multimeter set at 200 Ohms. The secondary reading was 13.9 ohms with the multimeter set to 20K ohms. Is this good readings? Did I take the readings correctly?

The battery gave a reading of 11.95 volts. Not great but not bad either? As its cranking the engine fine with spark plug out.

So is there a way I can check or defeat the kill switch? What else should I check and how?

[High On Octane]

Coil appears to be good, but your battery is extremely low.  i don't know much about the Eureka system, but most EI ignitions won't fire if they drop below 12v.  If it is only low from cranking the bike, then you definitely need to get it on a charger before it takes a crap.  Other possibilities; bad ignition fuse, bad kill switch, loose wire somewhere in the ignition, bad ground wire on the battery, or just a bad battery all together.  Regardless, you need to take that voltmeter and start doing some voltage and continuity testing.

[Dave1]

Hi thanks for comfirming the coil is fine. Ok will give the battery a charge. How do I check the ignition fuse? Is that the normal fuse? I would check on an RE? If so mine has been upgraded by the previous owner to a spade type fuse and is fine.

How do I check the kill switch?
I have pulled the ignition barrel where the key goes in, and all looks fine on the back of there, solders are good and no loose wires.

How do I do a voltage and continuity testing on the mentioned? I have a multimeter but I am clueless on electrics?

[Dave1]

Right the only obvious loose wires I could find are in these photo's. Two sets of wires which go to two different type of connectors, and a little ring connector, which has never been connected to anything since I've owned the bike!

I did look in the Eureka ignition the wires looked ok.

[High On Octane]

Continuity testing is simple.  On your voltmeter there will be a setting that looks like a bell.  On that setting, the voltmeter will chime when the circuit is completed, ie, if you touch the 2 probes together, it will chime.  This is a good function for testing circuits, basically, put 1 probe on 1 end of the circuit and the other probe at the other end.  If it chimes the circuit is complete and good, if it does not chime, there is a broken circuit.  As for fuses, you can test them as well using the continuity test, if it chimes the fuse is good, no chime = bad fuse.  The kill switch is best tested by removing the switch from the bar and exposing the switch internals.  Again, test to make sure the switch is opening and closing properly.

The ring connector is likely a ground wire and should likely be mounted to the bare chassis somewhere.  But don't quote me on that, I said likely.     

[Dave1]

Thanks for explaining, the multimeter does have the bell setting. So I will get on that when time allows! Light is starting to fade here now. Battery is on charge.

I have suspected what you say about the ring connector, but never bother to find out, as the bike has always worked.. Any suggestions where that ring connector may be from? Or can I just ground it anywhere?

[Blltrdr]

That wire looks like the points wire that came off the coil. With the new ignition it probably is not used.

I have a PVL coil that I tested for comparison 3.6 ohm, 5.5 kohm.

[Dave1]

So did you test your coil the same way as me Blltrdr? If so then would my secondary circuit reading of 13.9 be 13900 kohm? Not good at this sort of thing!

[Blltrdr]

It would be 13.9 kohm or 13900 ohm. I compared my PVL coil to my original Lucas and it measured 7.7 kohm.

Is your PVL coil a 101 220? If so, I would suspect secondary reading to be out of spec.

Not sure if you have removed the coil to test it, but you should be testing it with the wires removed.

[Dave1]

No I have not removed the wires, I tested the coil with wires in place.

[Dave1]

Today I have tested the continuity of the kill switch,ignition barrel, and fuse. All are good. On the ignition barrel I tested the black and red wire. Which I took to be positive and negative.

The battery is now reading 12.65 volts on the multimeter.

Answer my this guys, if I hold onto the spark plug cap or the HT lead with my hand when cranking the engine over, should I not get a shock? I seem to remember that I should.

I am running out of ideas?

[Dave1]

I now have the coil off the bike and here are the readings.

With the multimeter set at 20K secondary circuit reading 5.30 ohm. With the multimeter set to 200 the primary circuit reading was 03.9 ohm.

With the multimeter set at 20K the HT reads 9.55.

When I do continuity testing on the coil on the primary circuit it rings, on the secondary circuit it does not ring. The HT lead does not ring.

[ace.cafe]

It seems to me that the coil has a bad secondary. I think you need a new coil.

[Dave1]

Blltrdr and Ace I think you could be right. The coil code is 101 220 on my PVL. What should the specs be for this coil?

[ace.cafe]

Try to match the same primary resistance, generally 3.2-4 ohms. Secondary restance should be 8000 ohms or higher if possible. A Bosch Blue coil should be available in this range, and they work well for a fair price.

[Blltrdr]

You have the same coil as I do. I think your secondary reading of 5.3 ohm should actually be read as kohm which would make your ohm measurements close to mine that I listed a few post ago. I found this coil produced a weak spark so I changed to a Pertronix coil. The Bosch Blue coil Ace mentions should be able to source locally.

[Dave1]

Hello yes I think the secondary circuit should be read as Kohm as I tested it in the 20K setting on the multimeter.

This now beggers the question, if the coil is in fact ok, then what is causing my ignition circuit to have no spark!? What does everyone recommend?

[High On Octane]

Loose spark plug cap?  Completely fouled plug?  A short in the ignition wiring?

[Dave1]

Have two brand new plugs, plug cap isn't loose. It is looking like it might be a short somewhere. Is there a way I can test with the multimeter for a short?

[ace.cafe]

I recommend that you get a coil that works.

[Dave1]

Thanks Ace, I know if you insist on a solution twice then that is the problem. I have done some research since my last post. It seems a coil with a primary circuit range of 3-4 ohm should have a secondary range around the 8 ohm range. So I definitely think it is the coil now.

[ace.cafe]

Thanks Ace, I know if you insist on a solution twice then that is the problem. I have done some research since my last post. It seems a coil with a primary circuit range of 3-4 ohm should have a secondary range around the 8 ohm range. So I definitely think it is the coil now.

That would be a secondary in the 8000 ohm range.

[Dave1]

Yes it is.

[Dave1]

Thanks for all the hep guys. Today I put the old coil back in the bike. I connected all the wires. It now is producing a weak red/pink spark. According to my Hitchcocks manual. It could be defective HT lead, excessive electrode gap, loose connections, dirty pitted points, discharged battery, defective ht coil.

Well I know it isn't the ht lead, I don't have points, new spark plug so gap ok, I know it isn't a discharged battery( though it is old), could be loose connects, but most likely as has been said, bad coil.

[ace.cafe]

I now have the coil off the bike and here are the readings.

With the multimeter set at 20K secondary circuit reading 5.30 ohm. With the multimeter set to 200 the primary circuit reading was 03.9 ohm.

With the multimeter set at 20K the HT reads 9.55.

When I do continuity testing on the coil on the primary circuit it rings, on the secondary circuit it does not ring. The HT lead does not ring.

Thanks for all the hep guys. Today I put the old coil back in the bike. I connected all the wires. It now is producing a weak red/pink spark. According to my Hitchcocks manual. It could be defective HT lead, excessive electrode gap, loose connections, dirty pitted points, discharged battery, defective ht coil.

Well I know it isn't the ht lead, I don't have points, new spark plug so gap ok, I know it isn't a discharged battery( though it is old), could be loose connects, but most likely as has been said, bad coil.

Secondary resistance of 5300 ohms divided by primary resistance of 3.9 ohms gives 1358.97 effective turns ratio.
1358.97 times 12v equals 16307.64 volts spark.

That is a very weak coil.
It also seems to measure out with a resistor HT wire, and if you have the usual resisror plug in it, that is doubling up the resistors which also cuts output.

Generally, 20000v output is bare minimum, and that's weak. Typically we would like to see 30000v spark, and 40000v would be real nice.
16000v is not good.

[Dave1]

Thanks Ace, for sharing the maths with me. I have just ordered the Pertronix Flame Thrower 1 coil. Which should produce 40,000 volts.

[Blltrdr]

Thanks Ace, for sharing the maths with me. I have just ordered the Pertronix Flame Thrower 1 coil. Which should produce 40,000 volts.

That is the same coil I replaced my PVL coil with. Make sure you get the mounting strap for that coil. Fat beefy coil.

[Dave1]

Will the standard Lucas strap not work? As the bike isn't currently fitted with the PVL strap.

[Blltrdr]

Will the standard Lucas strap not work? As the bike isn't currently fitted with the PVL strap.

I would advise you to order the strap. Trust me!

[Dave1]

Blltrdr did you test your Pertonix coil with a voltmeter when you took delivery of it?

I think I've been sent a rubbish coil. The secondary winding is not giving a reading, and the primary winding is giving a reading of 3.5 ohms.

[Blltrdr]

Yes tested but can't remember the readings. No problems with mine. Double check your MM setting for that secondary reading. Hopefully it's OK.

[High On Octane]

Yes tested but can't remember the readings. No problems with mine. Double check your MM setting for that secondary reading. Hopefully it's OK.

Good point.  Was the multimeter on 20K ohms for the secondary reading?

[Dave1]

Yes it was on 20K setting, a triple checked it then I triple checked it again. Couldn't believe my luck. Retailer I brought it from was really good. No quibble, send it back and they will check and exchange and they paid for the return postage.

[Dave1]

Well guys in the end the company I ordered the coil from, had to send it back to Pertronix, because it is unusual for a coil to have a problem and Pertronix wanted to investigate, which is good. It would take 3 weeks, the company I brought the Pertronix coil from wanted me to wait 3 weeks until the out come was decided( a new coil or not ). Which is bad customer service really. As they could of just sent me another replacement coil, if Pertronix decided the coil was bad, Pertronix could of just sent another coil free or refunded the company money. If they decided there was nothing wrong, the company I brought the product from could of just sent the coil to someone else! ( which obviously there was something wrong )

Anyway as I was in the 14 day cool off period, I just asked for a refund and ordered another Pertronix coil from a rival company. The coil arrived today, and tested fine.

So now I am going to order some normal copper core ht lead, and also a racing ht lead with 40 copper strands, which is suppose to have a even lower resistance. Going to order a meter of both and then test the resistance of both, the ht lead with the least resistance will be used. The spark plug I am using is the NGK Iridium plug with a resistor. Should make for one strong set up.

[Blltrdr]

No need to order that wire. Go to your nearest O'Reilley Auto Parts and buy it by the foot. Bought 5' for my ZG1200 last year. Great stuff.

[Dave1]

That would be a fine thing, if I lived in the states. I live in the Uk. Most auto parts stores on the high streets here only really cater to cars. 

[High On Octane]

I'm sure you can find an auto parts store locally that sells HT cable in bulk.  Not sure what you have for stores there, but anyone that sells parts for older cars should have HT cable on bulk rolls.

[Dave1]

I may of been able to buy normal copper core ht lead in a store but I wouldn't hold my breath. The main auto store now in the UK is Halfords. They hardly keep and spare parts for new cars let aloan old cars. Last time I went it, to get even a spark plug for my enfield( which I have done before ) I was told they hardly keep any parts anymore prefering to order them in for customers. The whole point of a vonvient store is you go in find and buy what your looking for and leave. If I have to wait for the store to order it in, I just as well order it through the internet! Plus I don't live close to a auto store anyway with free parking. So I am really better off ordering online like I have already done. Id be very surprised if you found racing ht lead in the shops anyway.

[Blown265]

G'day guys

Did a quick resistance and voltage comparison on a few Bullet coils today- the factory Lucas, PVL, and Pertronix 'Flame Thrower'. The measured results were interesting:

Lucas 3.2 ohm , 7500 ohm, giving 28100v (at 12v)
PVL 4.1 ohm, 6300 ohm, giving 18400v (at 12v)
Pertronix 3.4 ohm, 10300 ohm, giving 36400v (at 12v)

Assuming each of the coils were in factory spec, it makes the factory coil a better choice than the aftermarket PVL, and not surprisingly, explains why the spark with the Pertronix is so much stronger than the other two.

Regards
Paul

Lucas

[shaji]

Friends: I've a 2008 Bullet 500cc. It has both kick-start and electric start. This week, I tried to electric start and it keeps making a "Wheee" sound. Looks like it trying to start, but goes in vain.
 I checked the battery it has above 12v. When I try to kick start, it feels heavy as if the kicker doesn't want to go. After getting the ammeter to middle (by releasing compression switch), I was able to do one kick, but immediately, I feel the kicker tight.
I followed all typical starting steps mentioned above and still it doesn't start not I feel the kicker goes freely. With help of my friend I was able to push start. Now I am able to push start every time, but not kickstart or electric start. Any ideas?

[gremlin]

Secondary resistance of 5300 ohms divided by primary resistance of 3.9 ohms gives 1358.97 effective turns ratio........

Please don't confuse Ohms and Turns .....  You are doing a dis-service to your "customers".

Another pet peeve .....  People who actually believe higher turns ratio = more voltage at the plug.

The voltage at the plug will be what is required to jump the gap.  If you keep the same electrode spacing, your plug voltage will stay the same.  More turns = more gap in the plug.  A valid argument can be made that  adding a higher turns ratio coil without opening up the plug electrodes can actually reduce the reliability of ignition (owing to impedance mis-match and reflected energy).

 

[gremlin]

.......So now I am going to order some normal copper core ht lead, and also a racing ht lead with 40 copper strands, ....... and then test the resistance of both, the ht lead with the least resistance will be used........

Use the higher strand count wire, even if it has a higher DC resistance.  The "risetime" of your ignition pulse has some high frequency components to it.  High frequency currents "rise-up" and are propagated on the surface of electric wire (also known as the "skin effect"). 

By using the higher strand-count wire you have more surface area for the skin effect to utilize, and therefore better pulse propagation with less delay.

summary --> use the higher strand count cable.

[singhg5]

Please don't confuse Ohms and Turns .....  You are doing a dis-service to your "customers".

Another pet peeve .....  People who actually believe higher turns ratio = more voltage at the plug.

The voltage at the plug will be what is required to jump the gap.  If you keep the same electrode spacing, your plug voltage will stay the same. More turns = more gap in the plug. 

A valid argument can be made that  adding a higher turns ratio coil without opening up the plug electrodes can actually reduce the reliability of ignition (owing to impedance mis-match and reflected energy).

Three questions -

i) If voltage of spark plug depends on electrode spacing, what is the numerical value (Volts) of a typical spark plug of say 0.9 mm electrode gap ?

ii) Does the electrode material or design affect voltage, for same spacing - say nickel alloy eletrodes vs platinum or iridum electrodes of 0.9 mm gap, would they have different volts during spark ? 

Or is it mostly determined by the environment around them - atmospheric pressure in the combustion chamber, temperature, gaseous composition around the electrodes ? 

iii)  Is there a graph that shows volts on spark plug vs gap in its electrodes ?

iv)  Can you explain what does ignition reliability is reduced mean ? .... 'adding a higher turns ratio coil without opening up the plug electrodes can actually reduce the reliability of ignition'. Does this mean ignition coil does not fire sometimes ?  Should very high energy output ignition coils not be used if spark plug gap is not matched for it ? 

My three questions become four, five,...

[Arizoni]

While we're pestering ole' Gremlin, I'll have to ask:

Given the required voltage to jump the spark plug gap is fairly constant at a constant spark plug gap distance and constant cylinder chamber pressure, wouldn't a coil with a larger turn ratio be more likely to successfully create a spark if the combustion chamber pressure increased?

I ask because it is my understanding that an increase in the combustion chamber pressure greatly raises the voltage required to create a spark of a fixed distance.
This change can occur when going from a partially open throttle to a wide open throttle.

[gremlin]

Three questions -

i) If voltage of spark plug depends on electrode spacing, what is the numerical value (Volts) of a typical spark plug of say 0.9 mm electrode gap ?

ii) Does the electrode material or design affect voltage, for same spacing - say nickel alloy eletrodes vs platinum or iridum electrodes of 0.9 mm gap, would they have different volts during spark ? 

Or is it mostly determined by the environment around them - atmospheric pressure in the combustion chamber, temperature, gaseous composition around the electrodes ? 

iii)  Is there a graph that shows volts on spark plug vs gap in its electrodes ?

iv)  Can you explain what does ignition reliability is reduced mean ? .... 'adding a higher turns ratio coil without opening up the plug electrodes can actually reduce the reliability of ignition'. Does this mean ignition coil does not fire sometimes ?  Should very high energy output ignition coils not be used if spark plug gap is not matched for it ? 

My three questions become four, five,...

ia =>  I cannot confidently quote you a number for this, it will depend on the following additional variables:  humidity, mixture strength, and compression.  http://naca.central.cranfield.ac.uk/reports/1925/naca-report-202.pdf

iia =>  It is mostly determined by the environment.

iiia =>  this has some examples .... http://naca.central.cranfield.ac.uk/reports/1925/naca-report-202.pdf

IVa =>  A complete discussion of this would involve the "smith chart" and transmission (electrical, not mechanical) theory.  Please understand the difference between a "High Energy" coil and a "High Voltage" (high turns ratio) coil, they are not the same thing.   But, to illustrate .....  the effectiveness (reliability) of ignition is the transfer of energy from the spark to the gaseous environment.  If the spark is INTENSE, but, short lived. it can become ineffective.

[gremlin]

While we're pestering ole' Gremlin, I'll have to ask:

Given the required voltage to jump the spark plug gap is fairly constant at a constant spark plug gap distance and constant cylinder chamber pressure, wouldn't a coil with a larger turn ratio be more likely to successfully create a spark if the combustion chamber pressure increased?

I ask because it is my understanding that an increase in the combustion chamber pressure greatly raises the voltage required to create a spark of a fixed distance.
This change can occur when going from a partially open throttle to a wide open throttle.

Truth.

One finding that may interest you ....  the voltage increase is linear (not exponential) up to 10 atmospheres (10:1) but then increases at a slower pace above that.


However ..... if the coil primary saturates at say 1 watt (an arbitrary number) additional turns on the secondary will not provide more than 1 watt to the plug.

Then if you raise the secondary voltage 50%, you will have a shorter lived spark.

[singhg5]

iiia =>  this has some examples .... http://naca.central.cranfield.ac.uk/reports/1925/naca-report-202.pdf


IVa =>  A complete discussion of this would involve the "smith chart" and transmission (electrical, not mechanical) theory.  Please understand the difference between a "High Energy" coil and a "High Voltage" (high turns ratio) coil, they are not the same thing.   But, to illustrate .....  the effectiveness (reliability) of ignition is the transfer of energy from the spark to the gaseous environment.  If the spark is INTENSE, but, short lived. it can become ineffective.

That link has answered so many of my questions, Exactly what I was looking for WOW  !

From my quick read of that link, here is a bit of summary in simple and generalized terms as best as I understand. Don't quote me on what I am writing here because it is not based on detailed analysis. This is a quick gist. Though Gremlin or anyone can add, subtract or improve on it.

Higher pressure and higher temperature have opposite effects on sparking voltage.

Higher pressure hinders discharge of spark - requires higher voltage to produce spark.

Higher temperature assists discharge of spark. Any change that raises temperature such as high compression ratio or opening throttle will tend to lower the sparking voltage.

At room temperature in lab conditions a spark plug of 0.9 mm electrode gap takes about 4000 volts to produce spark.

In combustion chamber spark plug requires higher voltage to produce spark - about 1.4 to 2.4 times higher than that required at room temperature. There is a bi-modal distribution depending on the construction of spark plug - whether spark plug is hot or cold type, respectively.

Thanks G !

PS - Finally DURATION of spark - short vs long lived - could affect the performance. Something that was missing in the conversation on spark and spark plugs.

[ace.cafe]

Please don't confuse Ohms and Turns .....  You are doing a dis-service to your "customers".

Another pet peeve .....  People who actually believe higher turns ratio = more voltage at the plug.

The voltage at the plug will be what is required to jump the gap.  If you keep the same electrode spacing, your plug voltage will stay the same.  More turns = more gap in the plug.  A valid argument can be made that  adding a higher turns ratio coil without opening up the plug electrodes can actually reduce the reliability of ignition (owing to impedance mis-match and reflected energy).

Yes, sorry.
I did mix the terms.

[gremlin]

......PS - Finally DURATION of spark - short vs long lived - could affect the performance. Something that was missing in the conversation on spark and spark plugs.

http://spdispark.com/pages/frequently-asked-questions-spark-duration

[singhg5]

http://spdispark.com/pages/frequently-asked-questions-spark-duration

It is good that you put this new link here. 

Previous link to a different webpage did not connect, when I had tried last time. I was about to try again today but saw this new link which works.

Spark duration for inductive discharge is 1 milli second and capacitive discharge 50 micro second.

Thanks. 

Interesting analogy in there - for spark plug inside a combustion chamber is like standing in a hurricane, trying to light a mixture of buffeting winds and speedily falling fuel droplets as piston rushes towards TDC. How difficult is that ? Need the right wind velocity and exact moment a match is burned to light the mixture - otherwise match will blow out.

A video link of a programmable spark flame duration and intensity by SPDI technology.

https://www.youtube.com/watch?v=MN644ojBcdc

[Dave1]

Wow this thread has taken off, thanks for the advice everyone, I've already built the new HT lead. I did go with the higher strand lead, the resistance is very low. With the coil, lead, and plug I choose, I have one bright strong spark.

I put fresh fuel in the motorbike, and the bike started first push of the button. I have tuned the carb, and the bike runs and revs very well now. Very responsive with the TM32 carb, and I have managed to achieve a nice, slow, even idle.

[High On Octane]

Awesome!  Good to hear Dave!