Roketa 50cc no spark  By  scoot315 (Read 5,429 times)

Ran before according to my buddy. Said it had been sitting for awhile and battery was dead and the throttle twisted hard.

I cleaned the carb, replaced the throttle cable and tried firing it back up.

I'm gonna follow this again and check out voltage's and trace the wires for you guys tomorrow. We'll go from there, but I know before I tried "jumping" it, the scooter would turn over with the battery. After the jump, no turning over at all. Had to try and kick it, but there was no spark

No I didn't put them on backwards. I got it to turn over a few times when I tried, but then something made a pop sound and then nothing.

Here are some of the pics for you guys. Green and black in the middle go to the ignition coil. Blue goes to the pickup on the magneto. Green and black in the two plug appear to be going to the kill switch, although the black on the kill switch is black with white stripe and in the cdi it isn't.





For some reason photobucket doesn't show the thumbnail but click on it and you'll see them.

what do you mean by poping ? was it one time pop ? smell anything smoke ?

John

Can't get the photobucket img links to work. Not sure what I am doing wrong here, it works on every other forum

tvnacman the battery was dying as it didn't hold much of a charge anymore and then I thought I could use my car as a large battery to keep trying to get it to come to life. Hooked some jumper cables up and it cranked over a couple more times and it made a pop sound. Prior to that I had spark and it turned over. After this pop there was no spark and wouldn't turn over with the jumpers anymore. Checked the fuse, looked ok, thought I checked the resistance of it. Anyways, changed to a blade type fuse and still no spark.

Tomorrow I am gonna go through the no spark link on scootdawg forum and get back with some values.

When you made your voltage measurements were they made at the cdi plug, the black wire on your cdi plug (2 wire) should be the 32vac while cranking. The green wire on the 2pin plug on your cdi should be grounded when the key is in the off position. The way I test it is (connect to the positive battery cable the the other probe/lead to the in your case green on the two wire plug. You should get 12vdc or a light (if using test light) then turn the ignition on and you should loose the 12vdc or light. )

John

Got in late on this and labeled the CDI wires:




The 3 plug is dead on and the two plug is easy enough to check and it is very common for the Chinese to change wire colors especially on the 50cc scooters. He said he had black/white at the kill switch and I have seen them take the black/white from the key ignition switch and the kill switch combine them and either go to the CDI with black or green.

TV mentioned the way to test the green wire and he can do it by ohming it or with a test light also. He can test both the ignition switch and the kill switch with either a test light or multi-meter.

We need to remember that if this wire is grounded out there will be no spark. With the key off it is automatically grounded out so it needs to be checked this way.

(1) Turn the key switch to the on position
(2) make sure kill switch is in the engine run position
(3) test green wire with test light or multimeter with test light it should not light up and by ohms it should have no resistance.

Should the test light come on or the meter read resistance then you have one or more of the following possibilities:

(1) grounded out kill wire going to the CDI
(2) bad ignition key switch
(3) bad kill switch on the handlebars

Should the green wire on the 2-plug test out then it is in the right place on the plug.

The black or whatever color wire it is should be the AC feed wire from the stator and if it does indeed have 32Vac on it with the engine turning over it is correct and in the right place on the plug.

I noticed the wires on the coil in your picture. Those spade connectors don't look like the common connectors the Chinese use, they look like a common one that you can buy at the auto parts? Has this scooters wiring been messed with or altered? The yellow/black is correct but the other wire should go to ground and it's unclear as to it's color in the picture? Need to trace this wire.

JR

JR,

Great detailed info. I'll bring one of our better multimeters home tonight and check this out. I did the spade connectors, we use this in our test lab and connections that were on there were bad or going to be bad shortly. You said that the killswitch wire being black/white stripe there, and only black at the CDI could be a wiring fault as well, or at least that's how I interpreted that. Does that make sense?

Just so I have this right, tv/JR I want to go from the green wire (killswitch) to the battery positive while have the key on and killswitch in "run" as well correct? And then for checking the pulse coming from the magneto, I want to tap from the black in the 2 pin CDI to ground and see what kinda voltage I am getting correct?