PX won´t start
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Hooked
Vespa P200E, 125 Primavera, COSA 200
Joined: 19 May 2009
Posts: 136
Location: Moscow, Russia
Wed Jul 08, 2009 12:19 am quote
Hi there!

Yesterday they finally brought my "new" '97 PX150E.
She is in veeery good condition, most of the details look brand new,
xcept for the rear shock - pretty rusty.

The only problem is - she doesn't start.
No spark.

Changed the spark plug, stripped terminals - no signs of life.
there's a suspicious-looking fuse, seemed like it was made from several different fuses, and it is broken from one side.

May this be a problem?
Ossessionato
Joined: 23 Sep 2008
Posts: 2633

Wed Jul 08, 2009 7:17 am quote
It's more than likely your CDI (it's blue maybe black). I have a 2005 PX motor and it didn't have spark..changed the CDI and then got spark. Try to find a doner CDI that is working and see if you get any spark.
Moderator
1962 GS160mk1, 1963 GS160mk2, 1965 SS180, 1974 Rally 200, wife's LI150
Joined: 05 Mar 2007
Posts: 6940
Location: Pittsburgh, PA
Wed Jul 08, 2009 7:25 am quote
It's not your fuse.

Think of a vespa engine like this : The engine can run completely independent of any and all electrics. The battery and wiring harness are all there to just put juice to the horn and lights.

Now, what i would do to troubleshoot your spark problem :

The CDI is the little blue or black box that hangs off the back of your engine. It takes impulses and charge from the stator, and triggers the spark. There are 4 colored wires running INTO the CDI, and your sparkplug wire running out of it.

Uplug the outermost GREEN wire... the one closest to you and furthest from the engine. This is the contact that runs to all your kill circuits. If this tab gets grounded out, then you will have no spark. Therefore, if your stator is working, and your CDI is good, if you have the red / white / green wires running to your CDI and are not getting spark at the plug, then that's where the problem is isolated : plug, wire, CDI or stator.

If you pull the green wire on the outside and suddenly you have spark, then your green wire there is grounding out somewhere upstream.... this wire runs to your kill circuitry, so either the one on the handlebar or the ignition switch on the column are grounding out when they shouldn't be.
Ossessionato
Joined: 23 Sep 2008
Posts: 2633

Wed Jul 08, 2009 7:44 am quote
Rover Eric wrote:
It's not your fuse.

Think of a vespa engine like this : The engine can run completely independent of any and all electrics. The battery and wiring harness are all there to just put juice to the horn and lights.

Now, what i would do to troubleshoot your spark problem :

The CDI is the little blue or black box that hangs off the back of your engine. It takes impulses and charge from the stator, and triggers the spark. There are 4 colored wires running INTO the CDI, and your sparkplug wire running out of it.

Uplug the outermost GREEN wire... the one closest to you and furthest from the engine. This is the contact that runs to all your kill circuits. If this tab gets grounded out, then you will have no spark. Therefore, if your stator is working, and your CDI is good, if you have the red / white / green wires running to your CDI and are not getting spark at the plug, then that's where the problem is isolated : plug, wire, CDI or stator.

If you pull the green wire on the outside and suddenly you have spark, then your green wire there is grounding out somewhere upstream.... this wire runs to your kill circuitry, so either the one on the handlebar or the ignition switch on the column are grounding out when they shouldn't be.
HA...then I have a grounding out problem somewhere. I was able to pull the green wire and still have it start! I also can't get my headlight to work at the moment either I know now I have a grounding out problem. I suck. Sorry to hijack the thread.
Moderator
1962 GS160mk1, 1963 GS160mk2, 1965 SS180, 1974 Rally 200, wife's LI150
Joined: 05 Mar 2007
Posts: 6940
Location: Pittsburgh, PA
Wed Jul 08, 2009 7:47 am quote
what i mean is ...

with the green wire on the 4th tab...if you have NO spark...

...and then you pull that tab and HAVE spark, then either your kill switch circuits are engaged ( which , really, this is the way you WANT it to work ) ... or if all of your switches are set to RUN, then likely your green wire is grounding out somewhere along the way. All it has to do is for a stripped part of the wire to touch the frame when the 4th green tab is connected and you won't have any spark at the plug.
Ossessionato
Joined: 23 Sep 2008
Posts: 2633

Wed Jul 08, 2009 7:55 am quote
Rover Eric wrote:
what i mean is ...

with the green wire on the 4th tab...if you have NO spark...

...and then you pull that tab and HAVE spark, then either your kill switch circuits are engaged ( which , really, this is the way you WANT it to work ) ... or if all of your switches are set to RUN, then likely your green wire is grounding out somewhere along the way. All it has to do is for a stripped part of the wire to touch the frame when the 4th green tab is connected and you won't have any spark at the plug.
Can you come over really quick and fix my scoot?
Hooked
Vespa P200E, 125 Primavera, COSA 200
Joined: 19 May 2009
Posts: 136
Location: Moscow, Russia
Wed Jul 08, 2009 8:21 am quote
thanx, guys

she is at the dealer's right now.
they got problems with all their mechanix being on vacation or badly ill,
so nobody can really fix my vespa

tomorrow i'll try to go there and try it myself
Hooked
Vespa P200E, 125 Primavera, COSA 200
Joined: 19 May 2009
Posts: 136
Location: Moscow, Russia
Fri Jul 10, 2009 7:03 am quote
it turned out to be hall sensor fault.

now it's fixed allright, and tomorrow i'll pick her up))
Moderator
1962 GS160mk1, 1963 GS160mk2, 1965 SS180, 1974 Rally 200, wife's LI150
Joined: 05 Mar 2007
Posts: 6940
Location: Pittsburgh, PA
Fri Jul 10, 2009 7:10 am quote
Stator problem... makes sense.
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