bike wont start gilera 125.help please :)

hi mate , ok should i try a brand new cdi or second hand? and i have an alarm with an immobiliser but its not set up on the cdi i dont think , one of my mates set it up ages ago.

 

Try a second-hand unit, to keep the cost down. If a replacement CDI doesn't cure the problem then move on to the stator and rotor.

The pick-up is a coil that takes an RPM signal from the stator and feeds it into the CDI. The CDI then translates this into an ignition advance in degrees and provides a 12v feed to the low tension of the ignition coil. As the 12v is removed from the coil by the CDI, the plug sparks due to the collapsing voltage in the high tension circuit of the ignition coil.

 

ok thanks, il do that then, il try the cdi first and il let you know.

 

HANG ON.
If you have a flashing light on the dash when it is switched off then you have a factory fitted immobiliser. This is part of the cdi and iginition barrel/key setup. They have to be bought as a matching set or it has to go to the dealers for recoding. Mega bucks.
Do you have a flashing light on the dash when it is switched off?

 

He said that he had a separate immobiliser fitted, Steve. Why would he fit another one if the bike has one as standard?

Edit: It looks like the Gilera 125 might have the ACI501 immobiliser, from a quick search on eBay.

@ SPRunnerSP

Does your CDI look like this one?

 

The runners cdi is just an immobiliser if fitted, can fit aftermarket alarm as well if required. It might just be an alarm without the immobliser circuit wired in. I had this in the not too distant past with the other 125 runner i did, but he had the malossi cdi fitted which keeps the flashing dash led but bypasses the immobiliser.
To buy the malossi cdi is 155 quid, the standard cdi without the immobiliser circuit isn't too bad a price but i think has a different plug setup, and the cdi with the immobiliser needs the ignition barrel and key to match. Its horrendous.
To buy a new stator and pickup is about 40 quid i think.

 

right, i'm going back in the house now, still in the workshop

 

this is my alarm i have and i think the immobilizer was wired in also

 

and his the cdi my bike takes

 

standard non immobilised early model cdi, not too expensive to replace.

 

ok so should i replace this first, cos theres a few on ebay at the moment for £25

 

or do i replace the ignition coil?

 

I normally go through the connections first, then if that fails, start with the cheapest and work up.
You should be able to track down wiring diagrams to test the components before you replace them all.

 

hmmm ive checked all the wires are plugged in and tobe honest i wouldn't no where to start to test them.

 

Get the replacement CDI and in the meantime, I'll try and track down the wiring diagram for your bike. This way, you know that the new CDI is working, as the seller will have given some form of guarantee to that fact. The rest we can figure out while it arrives in the post.

Edit: Wiring Diagram below.


This confirms the wiring colours; red, brown, white, green and purple. Red and brown come from the ignition pickup on the stator. Purple is low tension to the coil, green is earth and white appears to be a 12v feed into the CDI unit. If you confirm that your wiring matches this then we can start to troubleshoot.

 

ok thanks alot for all the help i really appreciate it..

 

I'm not a Gilera specialist, but there are some things we can check. Do you have access to a voltmeter or a multimeter that can measure resistance as well as voltage? If not, I strongly recommend you buy a cheap one from eBay while you are buying the CDI unit as it's an essential diagnostic tool.

 

ok and no i dont have one, could you maybe link me to one on ebay hat would be suitable for the job. thanks merlin

 

Here you go, 5 quid. Bargain!

http://www.ebay.co.uk/itm/Digital-L..._Measurement_Equipment_ET&hash=item416f39842a

 

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  so soon as that arrives and the cdi il let you no