Modern Vespa

…there are three videos below. From what I've noticed most readers are only opening one of them…the one with the picture. Please open all in order. This will give you the full details. Thanks

Videos of problems. This was February 3, Saturday when the outside temperature was 63 degrees Fahrenheit.

Surging after a brief warm up and ride.
https://youtube.com/shorts/6kcwhs05CzM?feature=share

4 minutes after surging shutdown and restart
10 minutes after restart…no start
https://youtube.com/shorts/vYS_pLvEcRk?feature=share

There are three videos in the above post.

'Surging' video had 13 views.

The '10 minutes after' has 77 views.

The '4 minutes after' shutdown has 106 views.

The 'surge' video is the least watched but is the most revealing.

Take another look?

I suspect a air leak causing the oscillating and/or the fuel pump

fixed the video embedding for you

SteelBytes…thanks for fixing my post and making it more readable. Vespa still hasn't been fixed. Took it to a 'professional' nearly 5 star rated Vespa shop. Not fixed. Out nearly $300… I'm working on a new post and will refer back to this one once again stating about poor quality of work done and not fixing problems.

What was done to the bike before this started? What was replaced, ect? When did you replace the battery?
And why are you putting parts in the oven?
The motor does not sound right. How's the oil usage and are you finding any bright bits when you change it?

The motor will run the same at 6K rpms with or without the 02 sensor connected. The CDI ignores it once it gets there.

Sorry to ask a question you might have already covered... (it's difficult to read lengthly posts with no paragraph breaks) You mention that you have repeatedly checked the spark plug boot, wire and coil, and it passed your ohms test.

Have you actually replaced the plug wire and boot?

Have you tried screwing the plug boot on the wire another turn?

I ask this as you might have a good connection while you have the wire pulled out to test with an ohmmeter, but when installed back on the plug, there might be an intermittent connection. The symptoms you mention are almost the same I had on my '07 GTS with a dodgy spark plug boot.

Agreed. This sounds exactly like an air leak. Have you done some quick sprays with the engine running with some carb cleaner around the intake manifold and injector to see if the RPMs change? Also, if the exhaust gasket at the head or junction with the muffler is leaking, it can play hell with the idle and off idle running because it can affect the O2 sensor.

And did you clean the idle bypass?