Modern Vespa

Hello people,

just got a vespa sprint out of 2014 and having a issue.. It starts well and runs also well. But there are two things.

1 the rpms are not getting high. It stays at a certain rpm and it is not getting up. It also happens when i am not using the centre stand.
2 the rear wheel is not turning.

I have 2 video's that showcases the issue the vespa has.

I hope you guys can help me out with this issue.

Sounds like an immobilizer circuit. But it's a 50cc model. Did you recently do any work to it, like put in really heavy weights? Clutch and rear wheel look okay

1. Variator not moving in when accelerating.
2. Clutch not engaging, stuck, or worn pads.

Disassemble the variator, check the rollers, clean the slide bus.

Remove the clutch bell and check the pads. Replace if needed.

Motor runs, belt looks alright at first sight. Should not be a problem to fix.

Thank you guys, ii will have a look on it. I havent done any work on it yet.

the immobilizer system because it sends a signal to the coil when to fire and also limits the spark (Rev Limiter).

https://modernvespa.com/forum/topic8606

Maybe this will help?

Edit:

Cheked the clutch and rolls today. Has some wear but not that bad.

If it is a 50cc model, I don't think it has an immobilizer.

With the engine off and the scooter on the center stand, does the rear wheel spin freely? If not, is the rear brake dragging?

Did you check the exhaust?

Something like in this post of collbain 2000 from Jan 30, 2007 seems very plausible. (in the link waspmike shared)

The engine starts up and idle is perfect but when you turn the throttle then at a certain rpm the engine sound changes and the engine clearly does not ignite at every compression stroke, it runs irregular and clearly misses several compression strokes in between ignitions.

If engine rpm is indeed limited to 2000, then that is probably too low to have the clutch engaged.

So I would start with checking the key and the immobiliser system of your scooter (or better: have it checked because if there is something wrong with it you probably cannot fix it yourself)

That sounds like a virgin immobiliser, before it's been programmed with any keys.

If you have the master (brown) key you can try re-programming it.

I got it! I changed the cdi with another one. Thank god the issue is solved. This model has no immobilizer. I am gonna clean everything up and put everything back. Clean it til it's shining and put another picture of it! Thank you all for the help and idea's.

edit: cdi is not shown in the picture (was curious what that is)