Modern Vespa

hello

i've been having this issue since i get my scooter, aprilia sportcity 300 which is the same engine and almost the same transmission as gts. i'm posting this issue in the hope i could find a solution because on aprilia forum there's not much action.

the clutch starts vibrating after a few houndred kilometers, usually over about 200. i replaced the original clutch with another original one. it worked for ablut 1000km and started doing it again. tried deglazing it, i changed all the bearings, same issue.

i bought an adjustable malossi clutch and the story repeats. i am trying to hit the gas hard but it makes no difference ".

now it broke the bearing of the clutch, the radial one, not the needle one.

does anyone have any ideea what could other thing to check? it is driving me nuts.

The common link here is you as a rider. Do you use the throttle on a hill to keep the scooter from rolling back? Scooter clutch is binary, stopped or engaged and going. How long have you had the bike, did you buy it new, how many miles on it? If you want a better response, you might consider providing more information. Welcome to Modern Vespa.

Have you replaced the bearing yet? Could that have been the problem all along?

I believe bluecloud is referring to the bearing in the transmission cover. Stick your finger in it and rotate. Should be very smooth. Gritty and hard to spin, replace

i changed all the clutch bearings. now one of them is broken again. the slim one from the clutch wheel, the one in the transmission cover is good. also the needle bearing is good. as i already mentioned i tried going hard on gas at start but its not always feasible because if i have cars in from i need to follow them; in which case i just open the gas hard to engage the clutch and then i release gas so i don't increase the temperature on the clutch.

i'm thinking of adjusting the clutch for a higher rpm and more brutal engage, maybe would help.

The wear on those clutch pads seems very uneven. You might look at replacing the clutch springs and contra spring?

There is also a Torsion controller available that is pretty cheap, but effective in helping clutch engagement. It work as a cap on the contra spring to reduce friction, helping with smoother clutch engagement.

https://scooterpartsco.com/gts-250-drive-and-transmission-c-3637_3642_3780/malossi-torsion-controller-for-vespa-piaggio-150300-p-523.html

Is that a new clutch bell as well. It might be out of round causing some of your issues as well. You should check the runout on the inside the bell.

last time i sanded the clutch pad i hurried and made them round. today i did it again and now are flat .

does anyone know if this can be caused by removing the front pulley washer? i removed that sometime ago and now i have a better ratio for riding outside of the city.

i highly doubt the issue it's the clutch bell, i have 3 of them. two of them are runner less than 2000km.

the torsion controller it's like a bearing ?

The torsion controller is a plastic cap that goes on the end of the contra spring inside the clutch pack. Works a little bit like a bearing in that it's designed to reduce friction. It's a $10 part that work well in my experience.

It looks that one clutch shoe engages first. The faying surface of the shoes must be the same. Your variator is also malossi?

i will try and 3d print that cap but as far as i could saw it had a cap on top of the spring.

the variators are the original ones, with new and original rollers and belt.