Modern Vespa

Hi,
I'm new to the forum. I have two vespas, a 2003 PX200 which has never troubled me and a 2002 ET4 125. The ET4 is a recent purchase and has just about got me beaten with an electrical problem.

It starts and runs fine from cold, but after riding for a short while, it will not start again after it has been turned off. It will wind over but not fire.
B
Initially I thought this may be a fuel problem so have stripped and cleaned the carb, un-siezed the accelerator pump, reassembled and adjusted mixture and it runs very well now but still will not start from hot.

The problem is definitely ignition related as I have pulled the plug cap off and put another plug in it to see if it sparks and it does not. But if I leave it an hour or so and try again there is spark. Put the cap back on and it fires up and away I go again.

I don't know if this problem could be related to immobilizer or not. The scooter only came with the one black key but I would expect the immobilizer would not allow it to start at all if that was the problem.

Most times this has occured it has been after a short ride and after I have turned it off and gone to start again after a few minutes. No go. But it has also stopped on its own, once after I'd ridden about 15 minutes and was idling at a set of lights and it died and would not start again and another time after only about 5 minutes riding and while under acceleration it just cut out and died. I came back an hour later and started up and rode home.

The recurring theme here is that this scooter lulls me into a false sense of security and then leaves me stranded on the side of the road. Its driving me !@**! NUTS

Any ideas anyone?

Thanks
Toby

Had the same problem with my ET4 and it was the ignition which can be costly to replace however the good news is you can buy an immobilizer bypass unit from beedspeed which is easy to fit and will solve the problem.
Think there about £50.
Hope that hepls!

Thanks for your response.

Problem is not yet resolved.

I have replaced the CDI unit and ignition lock and key as a set at considerable cost and absolutely no change to symptoms. i.e. will start and run but cuts out (no spark) after 5 or 10 minutes running.

Not the CDI. perhaps the coil?
I have now replaced the coil. Road tested and it cut out as per usual after three laps around the block.

I'm now thinking ignition pickup coil? I think it is part of the stator assembly?

Any ideas?

thanks Toby

It *could be* a dry/broken joint inside the stator, which when all is hot has widened to be open circuit. I've only ever had that once, but it is a possibility. There must be one or two other places where that is a possible fault.

I'm reminded of a monitor I was repairing many years ago. It would switch the display off after five minutes or so, then switch it back on a minute later, and then remain stable. The fault would not occur with the cover off. Turned out there was a transistor that was heat sensitive, in that it had a temperature 'window' of ~2C where the collector was open circuit. Below or above that, all was OK. With the cover off it never got hot enough to go o/c. That was a bugger to find...

Sounds like your stator is fryed.

Thanks both.
I concur. I was hoping I might be able to replace ignition pickup only and not the complete stator assy but this does not look possible. Will order a stator and keep my fingers crossed.
Toby

I have this same problem currently (no pun intended) and I wonder if your replacement of the stator assembly or pickup only solved the issue?

Let me know. I am frustrated with the problem solving of this issue.

Yes it was the pickup coil and yes it is part of the stair assembly so replacing she stator solved it.

I parted with the ET and just have P series now. Less refined but so am I.

Toby
Happy