Modern Vespa

Hey guys
Sorry if I posted in the wrong section, mods please move if I did. But I got a 2011 lx150ie, I'm getting weak spark, only on my first crank after 5-10 mins of it sitting. So basically I get spark the whole time I crank it the first time but after that nada. If I wait I get spark again but like I said, not even enough to get it too run. The HT coil primary & secondary both are within ohm specs. Pulse gen coil ohms out, spark plug cap resistance is a little higher then the 5k ohm I think it's more like 8. But honestly I don't see that being a problem ?
Also I have No weird immobilizer flashes.
Battery's is above 12v, I'm running out of ideas of things to check.
Can anyone point me in the right direction ?
Even if it's just an idea of something I can check. Thanks guys, y'all always come through when I'm stuck on these god damn Italian stallions 😂 lol

I'd be changing out the spark plug cap - apart from the fact that they seem to be 'consumables' as they fail quite often - the 5k is what I'd expect. 8k as such would be no problem, but that's not the spec, so something's up in there. The spring gets corroded and makes poor contact, and the screw thread can come completely adrift. I always keep one as a spare.

Also I'd cut 3mm (1/8") off each end of the HT lead, and re-screw it into the coil and cap.

If it still has the same symptoms, then I'd be thinking the coil itself might have a heat related open circuit - again, not that uncommon, but not easily tested except by making a separate jig to soak test it on.

Ah so pretty much what your saying is the coil could test good & still be bad. I was afraid of that.
Probably gonna just order a coil tomorrow & see if that fixes my issues.
But just out of curiosity, just how much trouble would a soak test be ? How would one go about that ?

You'd need an oscillator at say 50 or 60 Hz, so mains frequency is good. This needs to trigger say 5ms 12V pulses into the coil. Then connect a spark plug.😊

So today I got in my new HT coil, Plugged her up, got really really nice blue spark. Consistent enough to put back together. Got it back together, ran for about 10 secs. Then nada, nothing. No spark.
Starting to think it's a stator issue. Hmmm

Update, so I really need some help now because I'm out of good ideas. Currently I have a new coil, new stator plate, new ht lead and boot. Now I will have enough spark too run, I get about a minute of run time before I get nothing again.
Sometimes after it kills I still have spark, sometimes I don't. Please someone point me in a direction of something I can check.
These fuel injected lx's are a pain 😫

You say battery's above 12V - I do hope it's above 12.6V when just sitting there, and stays above 13V as soon as the engine does run, even for a few seconds...

Yeah I even swapped out the battery, with a freshly charged one. It currently reads 12.5v after trying to crank.
As of right now, I have zero spark again. It's super inconsistent. When I get it too run again I'll check running voltage on the battery.
It's almost like the ecu is finding a fault that won't allow itself to set false perimeters for.
Hmmm 🤔

In which case I'd be considering testing with a new ECU - if you use the service key (not the master) then it should start and run, but no more than 2000rpm. If, and only if, it's then happy, you can program it to the keys, otherwise it can either be sent back (depends if you have a local friendly dealer) or just keep it as a spare for someone else.