Good afternoon all. My name is Justin. I recently finished my enlistment with the U.S. Army and decided to have some fun on four wheels. I've purchased a couple toys: pocket-bike, 2 four-wheelers, dune buggy, etc. I'm usually pretty good with repairs but I have a problem that I was hoping you more experienced individuals could help me with. IF YOU ARE THE ONE WHO IS RESPONSIBLE FOR SUCCESSFULLY HELPING ME RESOLVE THIS ISSUE, I WILL REWARD YOU. WE CAN CONVERSE PRIVATELY REGARDING WHAT YOU WOULD LIKE AS A REWARD, MONEY, PARTS, ETC.

The issue is with my 2006 Roketa 250cc air-cooled ATV(ATV-60-250). I'm not getting any spark to the plug. I've replaced the CDI box, Coil, and even the Stator without any success. The gentleman I purchased it from stated that he had only ridden the quad a handful of times until he parked it one day and it wouldn't start anymore. Below is a picture of my CDI box model, as I've noticed you guys usually need. I have a voltmeter handy and I'll be online in the garage ALL day, so please don't hesitate to chime in. Any assistance would be greatly appreciated guys. Thank you for your time

 

With the well detailed picture and the list of what you have done before, I'm ashamed to ask, but have you checked for a bad kill switch that is shorting out your spark? It seems to me you have covered most of the bases, and replaced the key elements in the ignition system,a bad wire or switch could be keeping the kill circuit active, keeping you from getting any spark. Have you ohmed out the sparkplug wire from the coil, or is that a molded in type that cant be replaced without the coil? I have seen plugs go bad, rare, but possible, have you tried a new plug and see if you have spark with it grounded to the motor? speaking of ground, make sure there is no corrosion under the frame ground wire from the battery, ignition modules, etc. that might keep the voltage from completing the circuit. Sounds like you have a plan of attack, and have done a good job so far, keep us informed.

And thank you for you service to our country !!

 

I did indeed check the kill switch, it kills all power though. Which I'm not sure is normal. My other quad has a kill switch that cuts just the spark. This one won't even allow power to the starter when it's in kill mode.

There is no rust anywhere on this quad, it's borderline new

And I did try changing and grounding the spark plug . . . . .

Do you by chance know what readings I should get with the voltmeter?

 

Disconnect the CDI. Use a meter to probe the pins in the CDI connector:

1) Set all kill switches to the "run" position. Turn the ignition switch on. Measure the ground pin resistance to engine ground. Use the lowest resistance scale you have (like 2 ohms). You should read zero ohms.

2) Measure the resistance of the kill switch pin to the ground pin. You should have infinite ohms (open circuit). Turn off the ignition. The resistance should go to zero ohms.

3) Leave the ignition switch off and kill switches in the "run" position. Set your meter to the 2K ohm (2000 ohm) scale. Measure the resistance of the AC Ignition Power pin to the ground pin. You should see about 450 ohms.

4) Measure the resistance of the Trigger Pulse pin to the ground pin. You should see about 150 ohms.

5) Measure the resistance of the Ignition Coil pin to the ground pin. Use your lowest resistance scale. You should see 0.3 to 0.5 ohms.

6) Switch the meter to measure AC volts. Leave the CDI unplugged. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC.

7) Set your meter to measure AC volts on the lowest scale you have (2 volts AC would be ideal). Measure the AC voltage from the Trigger Pulse pin to the ground pin while cranking the engine. You should see 0.2 to 0.4 volts AC.

8) Plug the CDI back in. Measure the AC voltage on the Ignition Coil pin to engine ground. Probe through the harness wire insulation with your meter probe if you have to. On the 200 volt scale measure the AC voltage while cranking the engine. You should see mostly zero readings with occasional random numbers.

This will get a bunch of info that will point the way to the problem. Report back what you find and we can go from there. The tests above are geared toward an AC powered CDI. I think yours will be an AC powered CDI because it is a 2006. If in fact your CDI is DC powered it will become obvious in the test results above and we'll change directions at that time.

 

My buddy came over and checked out the quad today. We got many inconsistent readings from the voltage regulator. So I'm ordering one tonight. I will let you guys know how things turn out

 

Your regulator may or may not be bad, but this has *nothing* to do with spark issues.

Most likely your ignition system runs on its own AC supply coming from the stator. You need the battery (and the battery charging system including the regulator) to turn the engine with the starter motor. If you had a kick start or a pull rope you wouldn't need the battery (or regulator) at all.

Even if you have a DC powered ignition system (unlikely on a 2006), if the battery has enough charge to turn the starter motor is has way more than enough charge to run the ignition system.

 

I hear you, but I don't know what else to look into. All grounds are good. All harnesses are tight. There's no rust. I'm getting current to the coil, yet there isn't spark. It's quite possible that I got a new part that was faulty, although it is somewhat unlikely. I've attached the wiring diagram for my quad, if there is anything that catches your eye, please feel free to inform me. Thanks again for the help.

 

From your wiring diagram I see that the CDI is indeed AC powered from the stator (black/red wire).

So for you to get spark you need the following:

1) A good CDI, coil and spark plug.

2) Moderately high AC voltage from the stator to the CDI.

3) A trigger pulse from the stator to the CDI at the proper time.

4) The the kill switch connection to the CDI must not be grounded by any of the kill switches on the quad.

5) All the wiring between these parts has to be correct.

If you look back a couple posts you will see that I provided an outline of tests to do. The first check was to see if the kill switch circuitry was killing spark at the CDI (which is the number one cause of no spark). Then there was some continuity checks to see if the wiring to and from the stator were hooked up correctly. Then there was some dynamic tests to see if the stator AC power and trigger lines were producing the proper voltages to the CDI at cranking speeds. Finally there was a test to see if the CDI was getting triggered and producing any output at all going to the ignition coil.

There are many ways to solve a problem. Very often one can solve problems by just random fiddling, but sometimes that strategy doesn't work. In those cases you need to use logic, science, and careful measurements to narrow down the possibilities.

Not everything in the ignition system can be measured with a simple meter, but a lot of it can. And if the measurements don't find the problem outright, the results from those measurements can at least eliminate a lot of of possible troubleshooting dead ends.

 

I forgot to address this issue in my last post...

How exactly did you determine that you were getting "current to the coil"? This isn't an easy measurement to make with just a meter, and subject to a lot of variation between different meters. I'm just curious about how you measured this, and what exactly were the results of these measurements? I'm looking for any information that gives clues to the problem...

 

We determined that the coil was getting current from the reading on the voltmeter. I can't recall exactly what it read, but the reading did increase when the engine was attempting to start. I haven't had a chance to try your tests yet, but hopefully tonight I will be able to test everything and I will post the results. Thanks again for sticking with me