Modern Vespa

Hi all,

Got a new to me 4 stroke lx50 with 850 total miles. Not sure the year maybe 2012. And this seems legit. There is very little wear on the belt and clutch. Tires are original too.

it runs fine after a carb cleaning but will not drive. On the center stand the wheel rotates a bit with the engine. Faster with more rpm's but not full tilt. And nothing when sitting on the wheels.

All the drive components seem to be in perfect condition.the clutch pads are in spec and there is minimal dust and wear. The variator weights are not flat spotted or broken. I'm stumped. What could I be missing here.

Check carburettor

How do you define runs fine? Fires up and idles smooth, rpms increase as you give it gas? If you get nothing past idlle, reset the diaphragm. Use a thin layer of silicone grease around the lip. It can look fine, but still not be completely in place. Number 11 - Welcome to Modern Vespa.

I'm confused. Is the problem that the engine won't rev up, or that the engine does rev up but the rear wheel does not push the scooter forward?

Revs but doesn't move?

Points to clutch or splined interface between vario backing plate and crank.

Unlikely but possible broken contra spring or stuck shoes at the clutch.

Loose crank nut can cause damage to splines at backing plate and/or crank.

Doubtful a bike with 800 miles has any type of CVT problem. Revisit your work on the carburetor.

Does the nut that holds the centrifugal clutch on, go through the cover over the whole drive system. Some scooters it does, some it does not. If not, then take off the cover and start the scooter and watch what happens when you rev it up. What spins and what does not spin, but should?

make sure there's still an air cleaner. It sounds like the carb isn't transitioning from the pilot to the main jet. Run a wire through the main jet. If you can't, it's clogged.

Check the drive belt. A worn or glazed belt can slip on the variator when under load, which explains why it spins on the stand but won't move you. Even if it looks okay, replace it. It's the most common cause for this exact symptom.