2001 Vespa ET4 50 4T – Loud rubbing noise, heavy vibrations, low power after sitting 3 years
Hi everyone,
I need some help diagnosing my 2001 Vespa ET4 50 4T (ZAPC261).
The scooter sat unused in a garage for 3 years.
The previous owner told me the cylinder and piston were replaced 3 years ago. His son rode it for about 2–3 weeks, then the scooter was parked for the next 3 years.
Original problem
The scooter wouldn’t start.
After taking the engine apart, I found that the camshaft sprocket bolt had come loose, which caused the cam timing to jump.
I reinstalled and tightened the camshaft sprocket, re-timed the engine, adjusted the valve clearances, changed the engine oil and cleaned the oil strainer.
After that, the scooter started immediately and idles perfectly.
Current symptoms
Since it started running again, I now have:
A loud rubbing/grinding noise from the CVT/transmission side (not a squeak or knocking noise).
Strong vibrations throughout the scooter.
The engine revs, but only if I accelerate slowly and progressively.
I rode it for a few meters and it moves, but it clearly lacks power.
What I’ve checked
Removed the CVT cover.
Drive belt looks OK, not cracked and not excessively hard despite sitting for 3 years.
Gearbox oil level is correct.
No broken teeth on the Bendix or the starter ring gear.
However, the Bendix touches the variator starter ring gear, although I don’t think that’s what causes the heavy vibrations.
The clutch bell appears slightly warped, but I’m not completely sure.
The kick starter mechanism is in poor condition. It sometimes stays stuck down, and I can clearly see wear marks inside the CVT cover where the kick starter mechanism has been rubbing.
The rear wheel has a slight amount of play with a small “clunk”.
When I spin the rear wheel by hand, I can hear a rubbing noise, even with the engine off.
My question
What do you think is the most likely cause?
Faulty Bendix?
Variator?
Warped clutch bell?
Gearbox bearing?
Rear wheel bearing?
Final reduction gearbox?
Kick starter mechanism rubbing?
Something else?
I’m attaching photos and videos of the noise.
Any advice from people familiar with Piaggio/Vespa 4T engines would be greatly appreciated. Thanks!