Yet another Leopard "No Spark" thread…

[Avi Goldberg]

I have been seeking the net for answers but to no avail. I recently bought a TaG kart, with an older, pre 09 IAME Parilla Leopard engine, did a complete strip down of the kart, fixed everything that seemed broken, put it all back together, pushed the start button and although the motor turns, the carb setting screws are set at the default positions, fuel clearly filling the tubes but the motor doesn’t start. I connected a new fully charged battery but still it doesn’t start. I don’t know if the kart was running properly prior to my purchase.

I began checking for spark, I pulled the plug, made sure there is contact between the plug and the engine body, you guessed it, no spark… changed a few plugs, still no spark. I disconnected the wire that goes to the coil, took another wire and connected it directly to the blue coil and on the other side of the wire touched the positive terminal of the battery just briefly to see if there is a spark (This procedure tests the grounding, plug, coil, plug wire and head connection all at once) and there you go, it gives a spark. Now that means it’s either the stator or the power pack.

Now it’s time I pulled out my DVM, checked the ground resistance, all good. I then decided to check my stator’s resistance… I have the values now but I couldn’t find what the correct values are so I’d know if my stator is at fault or my power pack. My question is, does anyone here own a spare stator who can measure the stator’s resistance so I can compare the measurements?

I also checked the voltage on the coil wire and the maximum was 1.6V but my DVM could be wrong, could any of you please describe how to measure the voltage on the coil trigger wire?

Thank you all

Avi

[Avi Goldberg]

I painted the wiring diagram and all the measurements I took:

I hope it’s clear…
Thank’s

[tony zambos]

Avi,
When you pulled the orginal plug out, was it wet?

LAD Specialties customer / tony kart / rotax / kt100

[Avi Goldberg]

No, it wasn’t wet. I don’t see how this is relevant though, we have one situation that we have a good spark via the small test I did and another situation were we don’t have spark at all, that’s when I press the start button. The difference between the two situations, if you take the battery out of the equation (I checked with three batteries) is the stator and the power pack. Fuel has nothing to do with it, That’s why I asked for the resistance measurements of the stator that would let me know if it’s the stator’s fault or the power box.

ThanX

Avi

[tony zambos]

The question was to rule out the possibility that fuel was not getting into the motor. If you cranked the motor for some time, there should have been plenty of fuel in the cylinder, hence a wet plug. Also, if you cranked it for awhile, pulled the plug and cranked the engine again, you should have had a mist out of the plug hole.
Your troubleshooting for an electrical problem seems to be spot on.

Good Luck.

LAD Specialties customer / tony kart / rotax / kt100

[Avi Goldberg]

Thank you for following up on my logic in this troubleshooting, it always helps to have someone else look at what I’m doing but from their own perspective.

I’m originally a motorcycle mechanic, I was really surprised to see IAME not publishing the resistance values of the stator. Measuring resistance is a very simple and common way to determine if the stator is in good working condition or not. Shame… Hope someone with a good working stator can measure so I may compare the values.

Avi

[Norm Clemo]

I have the exact same problem on my 09 Leopard. I have replaced the ignition module, coil, key, stator with no luck yet..

I do know some of the TAG’s will not turn the motor over fast enough to start – it is a common problem, have you tried an external starter? You may want to give it a try. I know it sounds counter-intuitive, you should get a spark but if the motor isn’t spinning fast enough it won’t work…When i bought my TAG the only way it would start is with the external starter. I put in a bigger battery, rewired the starter with heavier wire and now it starts ez with the starter – that is until it broke recently.

[Avi Goldberg]

You have the exact problem as me? Meaning your starter turns but you get no spark? If so you must do the “strike test” I did, that means you take out the plug, take an electric wire, at one end you connect it instead of the wire going into the coil and on the other end you strike the positive pole of the battery while someone else is watching the plug to see if there is a spark.

Don’t make a connection to the positive pole of the battery for more than a brief moment!! Only strike it like you try to light a match on it. Leave the ground wire going into the negative pole of the battery connected.

Let me know the result…

Avi

[Norm Clemo]

Thanks, I already tried that and it sparks, implying the coil is good… I replaced the coil, still no luck..

[tony zambos]

Norm,

Just a thought, since again you’ve done the logical replacements. Do have any wobble in the crank shaft that would cause the rotor to contact the stator?

LAD Specialties customer / tony kart / rotax / kt100

[Norm Clemo]

Tony,

Thanks for steering me to the rotor, it was the 1 thing I had not checked and was contemplating changing it as i had a spare which i got with the stator i bought a year ago… there is definitely no contact but it may have got damaged before i had the engine rebuilt several months ago, it does have some marks and scratches. Didn’t think such a simple thing could go wrong..

 

Avi I would recommend this is your next step as your symptoms appear exactly as mine were.

 

FYI I called my local Kart shop and they said ‘start replacing stuff’ thats what they would do..

[Norm Clemo]

No, recently rebuilt motor and i checked that- I have one more thing to try along these lines, recently I replaced the stator as some of the wires broke at the connector from vibration, I have since repaired them after buying a new one and looking to see what color went to what pin, but I never replaced the rotor which came with the new stator so it is my last shot. I’m not sure there is much to go wrong with the rotor ? but the do include a new one with the stator.. so maybe something there…

[Avi Goldberg]

Dear Tony,

When I took out the stator, I did see a few scratches on the stator that looked suspicious to me that were made from the rotor. How does that influence spark creation?

I will check later today if I have any kind of movement in the crank bearings and let you know.

Avi

[Avi Goldberg]

Norm,

If you did the “strike test” and it sparked, then you have either a power box issue or a defective stator. A wiring problem could also explain those symptom. If you have a DVM you may measure the resistance of your stator and use the values I got as a reference to compare to the measurements you take despite you having a slightly different stator. Actually you have two stators so you can compare one to another unless both are bad. Also measure the voltage on the wire going into the coil while pressing the start button and see what you get. Write the results here and we’ll take it from there.

Avi

[Norm Clemo]

Success, I replaced the rotor and now I have spark… Interesting as i dint think there was much to go wrong with the rotor.. but in hindsight, when you buy a stator you get a new rotor.. so lesson learned. I now have a spare coil, electronic module, keyswitch to throw in my toolbox.

[tony zambos]

Avi,
A few light scratches may have resulted from debris. Contact between the rotor and stator could cause a timing issue or no spark. They are generating timing or clock pulses to the ignition system. From what I’ve seen, the rotor and stator are sold as a set which makes me believe that they are a matched. But that theory could be all wrong.
That’s a good idea to have Norm compare his resistance reading with yours.

LAD Specialties customer / tony kart / rotax / kt100

[Avi Goldberg]

I’m on the hunt for parts at the moment but I’m kinda low on budget so I hope I can get a complete spare electric system at a  not so steep price. Then I’ll be able to replace parts and see which part is faulty. Till then I’m with the tools I already own and good advice from knowledgeable forum members.

Any way to buy only rotor without the stator?

I’m very happy for you Norm. Happy and safe racing.

Avi

[Sean S]

I saw this post and just now had time to pull the stator off and grab my second one. I had a problem with my spare that I bought from someone on here and never worked which made me think it was something else electrical. I ran the continuity tests and found that I wasn’t getting anything on the Blue and Red wires. I cut the housing away to find out that it has been tampered with and whoever made an attempt to solder it with 2 other pieces of wire, shrink wrap and tape, but didn’t make the best connection.

Here are the results from my current engine stator.
The number under are a second test a few minutes later.

Here are the results of the spare/hacked stator.

Avi,

Not sure about you guys, but do you think my spare is shot or is there anything else to check. I wasn’t getting the continuity sound on the blue and red wires even when I stripped away the jacket to the fresh wire, but i was getting the number read out which looks good… confused

Sean,

Tony Kart / Leopard

[Avi Goldberg]

Dear Sean,

I don’t think that 50 ohms should play the continuity sound, that is a substantial resistance compared to short.

Your ac and bc readings are what seems to be substantially different than mine although not that much different than each other. I bought a used working set  stator and rotor, when I get them I’ll remeasure and post my results.

Till then if someone can post their results that would be great.

Avi

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