No spark! Suggestions / Help needed (SOLVED!) By nalrac (Read 6,579 times)

[nalrac]

Hello everyone!

This is my first post. I'm the proud new owner of a silver 2007 Roketa Bali 150cc scooter

I bought the scooter knowing that it had a problem getting fire to the spark plug. The man that I purchased it from said that he thought the problem was either the CDI box or the stator. He also stated that the spark plug and coil were both "brand new" and had less that 100 miles on each. So, I replaced the CDI box and the problem persisted.

The problem specifically is that the spark plug doesn't fire about 90% of the time. Very rarely it will fire but will quickly stop and the engine will die. I found the great article (www.scooterdoc.proboards.com/index.cgi?board=electrical&action=display&thread=2524) on this forum that gives a step-by-step process for diagnosis and followed it. Here's what I found:

Spark Plug: No Spark (tried a different plug with the same result)
Coil: Didn't have another to swap out with but, as I said above, it's brand new anyway.
Ignition Switch: Tested OK
Kill Switch: Tested OK
Stator:
38 vAC - Red/Black wire from stator
.3 vAC - Red/White wire (to my knowledge, normally blue wire on most GY6's)

I also tried to test the resistance of the stator and these are the results:

Red/Black - Couldn't seem to complete the circuit. No reading whatsoever.
Red/White - 120+ Ohms

My questions are:

• Is the voltage that I'm getting from the stator enough to produce a spark or do I need to be in the 50 - 100v range?
  
• How can I test if the coil is getting power?
  
• Is there anything that I'm missing?
  

Thank you in advance! I can't wait to get this problem solved so I can enjoy my scoot!

Adam

[sprocket]

I would think it is the pick-up coil on the flywheel. It should be a minimum of .5 volts...

[nalrac]

OK. So, should remove the shroud & fan and test the resistance of the pickup coil directly? If so, how do I do that specifically and what reading should I expect?

Thanks!!!

[sprocket]

No, the voltages is all that is required.. the resistance tell you nothing....

[nalrac]

OK. So, I will confirm tonight. If I test the trigger wire and am getting less than .5 vAC then is it your opinion that my stator is toast?

[sprocket]

NO NO the pick-up coil has nothing to do with the actual stator... it sits on the outside of the flywheel.

It is a separate item.
www.scrappydogscooters.com/125_150_4-STROKE_PARTS.html

They call them an Ignition coil 3/4 of the way down the page

[nalrac]

Thanks for baring with me! I'm obviously a newbie at this (in case you couldn't tell).

So, now that I know we are talking about the "ignition coil" I understand. I actually suspected that it was the culprit but it's supposed to be "new".

Just for my information, how did you gather that from what I said in my original post? I didn't actually test the coil and the .3 vAC was coming from the trigger wire straight out of the stator.

[sprocket]

No I'm talking about the pick-up coil... scrappy calls it an ignition trigger pickup coil just to confuse everyone...

Attachments:

[nalrac]

Wow. Thanks for that. That really clears things up!

Do you also agree with the above regarding a possible ground?

[sprocket]

Sure grounds could be an issue... certainly the prime voltage to the CDI should be above 50 volts AC...

Mine is about 87 volts... and my pulse is about 1.4 volts...

Generally a pick-up pulse of .5VAC is considered the cut-off point.

To test your voltages from the stator just run a new wire from the engine to the frame. If the stator values go up... you know your original ground wire is bad...

I have two ground wires from the engine to the frame as a matter of course...one may go bad but both.. not likely...

[nalrac]

Alright guys! The plot thickens!

When I got home I ran another test on the stator and, to my surprise, I'm actually getting between 45 to 55 vAC from red/black wire and .4 to .7 vAC on the trigger wire. So, I'm not sure what to think about that.

The ground from the shroud to frame was indeed intact. I removed the fan shroud and looked at the wires there. Everything looked AOK to me. I haven't tried to run a second wire.

I also tested the ignition coil using the method outlined on this forum and got .3 on primary and 8.0 on secondary.

To top it off, another problem has developed. While using my car to charge the battery I tried to start it for about 15 minutes off and on while running some tests. After a while the engine stopped turning over and I smelled a slight "electrical burn" smell. Along with that, it was accompanied by a grinding/squeeking sound. I can hear the solenoid kicking in. The flywheel, on occasion, turns very slowly. However, the flywheel turns with little effort by hand. I suspect the starter burned out. What do you say?

BTW - I don't have a kick starter

Please, please help me figure this out. I'm already losing too much sleep these days

[nalrac]

Oh boy I guess this IS a lesson learned on my part!

I didn't consider to consequences of the amperage being too high and frying the battery, starter, solenoid. This is obviously a rookie mistake that I'll pay for (literally).

So, I think that I've narrowed down the problem enough to say that the lack of spark is the stator. Right?

Also, just to be clear; Is there anything specifically, other that the solenoid/solenoid relay and starter, that could have been affected by my ignorance? If put a screwdriver across the terminals on the solenoid and the starter turns then is there anything else I should check or should I be OK?

Luckily, I've already gotten this giant jigsaw puzzle of a scooter apart. So, I can get to pretty much anything I need.

Thanks for "baby sitting" me.

[nalrac]

Also, can I follow the procedures here www.scooterdoc.proboards.com/index.cgi?board=electrical&action=display&thread=940 and determine what is affected or is there more I need to check?

Thanks again.

[sprocket]

You can bridge the solenoid, but I suspect you have burned out the starter motor.

These aren't like cars... you can't sit and hold the starter button. The most you should press it is like for 2-3 seconds then wait for a 10 count and try again if it is not running...

Usually jumping from a running vehicle will effect the battery and take out the solenoid and CDI...

Hard to say...

[nalrac]

OK. Thanks. So, how's the best way to test the CDI?