Modern Vespa

Hi everyone,
I recently bought an older Piaggio MP3 400, model year 2009. I really like the concept of this scooter – it's quite unique. Overall, it's in decent condition, but there's one issue that's been bothering me.

When I accelerate, the handlebars tend to wobble slightly from side to side. The same thing happens when I let off the throttle. It's just a gentle wobble that doesn't occur during steady cruising.

The tires are almost new (Michelin City Grip, about 1500 km on them) and properly inflated. The variator belt is also new. I don't feel any play in the steering, although there seems to be some notching in the bearings. I'm planning to replace all the front suspension bearings soon.

Has anyone experienced this kind of behavior with the MP3 or a similar scooter?

Thanks in advance for your thoughts and suggestions – and please excuse my English, it's a machine translation.

Perhaps defective tires/wheels or worn/damaged suspension and/or steering components

steering bearings are shot , worn out, notched.

The notching will make it feel like that. It will also make it very hard to filter through traffic very slowly. You have to fight its desire to travel in a dead straight line.

Try the Gonzo mod first - quick easy way to put off changing the bearings for a bit:

Short term fix for "notch"? - It works...

To tight tightened headbearings can also cause this effect.
Typically at certain speeds.

I think I had the same feeling long time ago, but does it feel heavy when turning, if so, then they are the steering bearing, they need to be changed. I hope that helps.

So the advice from jimc works. It's not completely 100%, but the feeling is definitely better. Thx Gonzo