Possible Bad CDI By skafreak (Read 27,327 times)

[skafreak]

I will try that next if this does not work, but when I tested the stator, the pick-up coil seemed to be outputting a reasonable voltage. I don't know much about how they would fail though. It should essentially act as a binary signal, either on or off. When they fail, do they always fail to off, or will they sometimes pass a constant high voltage and not re-trigger the CDI?

[sprocket]

CDIs when they fail simply don't charge...however, they more often get old and the capacitors take longer and longer to charge...

More likely is the ignition coil.. these fail outright...usually open...

Pick-up coils either issue a pulse voltage or they don't...

[skafreak]

Well, to me that sounds like it is more likely the CDI since I sometimes can get the scooter to run. If the coil fails open, then I would have no chance of starting it. Either way, I figure I'll replace both and hope that it is up and running again.

[sprocket]

Sure try the CDI but I will bet it is the pick-up coil... I always carry a spare ignition coil, pick-up coil and CDI.

You are right about the ignition coil.. they just stop, or the work intermittent when hot. I suspect it is caused by a breakdown of insulation...

Here is a trick, put the ignition coil in the freezer overnight and see if it will run...you can do this with any electrical part on a scooter...if you think it is heat related... or you can spray the part with CO2 gas...to make it cold...sometimes compressed air works, but it is not too reliable..

[skafreak]

There is something one of us isn't understanding here. From what you've said, if the pickup coil is functioning, there will be a voltage out of it, and if not, there will be nothing. When the scooter is not starting, I am still getting a voltage out of the pickup coil going into the CDI. I don't have an oscilloscope to make sure that it is pulsing, but a multimeter shows that I am getting a voltage high enough to trigger what I would assume is a comparator in the CDI. What makes you think that under those circumstances, the pickup coil is bad? Do you think it is just outputting a constant voltage high enough to trigger it, or what?

[sprocket]

OK, have you got spark at the plug? Yes?

Run some gas down a vacuum line into the intake manifold, replace the hose and see if it will fire..

When was the last time you gapped the valves?

I have had pick-up coils work fine and then stop... it may show a pulse when you test it but there were many bad PCs on the 2008 model scooters... intermittent PCs are the norm.. often, but not always heat related...

So, I recommend you check the above and then start replacing parts...CDI, pick-up coil, ignition coil...

[skafreak]

Do I have spark at the plug? Sometimes, but not when it is not starting. I said that a few posts back... It does not seem to be heat related though. It sometimes works great cold, sometimes won't start cold. It sometimes will handle a long ride in 80 degree New Mexico sun, sometimes won't.

Either way, as I said, I have CDI and ignition coil on the way. They will be here Monday. I will toss them in. If it works, great, problem solved. If not, then I will measure the voltage out of the pickup coil when it is functioning and when it is not. If they don't match, I'll move on to replacing the pickup coil. If not, I'll probably toy around with a few ideas before placing the next order. Either way, I have the information I need at this point. Thanks.

[sprocket]

Hope it goes well for you...

[skafreak]

Switched out the CDI and the ignition coil and it has been running great since.

[sprocket]

Do you know which of the two it actual was... it may help others...to diagnose their problems.

[skafreak]

Not definitively, I just switched both out since they were both the stock parts and I want to slowly replace most everything on the bike. I would say 95% sure it was the CDI though.

[hank87]

Hi, I'm having exactly the same problem on my peugeot speedfight 2 50cc. Actually with the engine cold the scooter is almost not drivable (cut off when I open the throttle and doesn't move at all) but if i let it run for 10-15 minutes it becomes drivable but still cut off sometimes while driving and have less power.
Yesterday i checked the connectors of the ignition coil and cdi, and there was some water because the previous owner of the bike fitted some aftermarket body panels and they have many holes that they let the water go inside and wet the cables. I sprayed both the connectors with wd40 and i put some plastic to cover the holes.
This morning the problem was gone at 90%, it started easily from cold and was drivable, the power is back to normal, just a few times for a moment the engine cut off.
I bought a new ignition coil with cap, it's a naraku racing high tension coil, on the description says that has an output voltage of 31,000 Volt instead of 16,000 of the stock one. I'll fit it tomorrow, and will see if it solve the problems.

[jct842]

hank,
If you are still having problems might be best to start your own thread too. Engine numbers by kickstand on lower left side will better help identify your scooter since most chinese styles all follow the same few engine numbers although the plastic is different.

[hank87]

I don't think it's cinese, it's a peugeot speedfight 2 liquid cooled, 2 stroke.
Today the scooter is working properly, so I think the problem was the ignition coil.

[hank87]

Update: today the scooter it's not running again.
It started and ran perfectly for about 10 minutes then suddenly cut off and didn't wanted to go again, it switches on but if i open the throttle it die.
Same suggests?
The new cdi is 30£, it's a dellorto 8 pin that controls the oil pump as well.
Can be a problem of the pick up coil? Is better to change all the stator that cost 25£ or just the pick up coil that costs 11£?