Modern Vespa

Hi Guys,

My first post here! My cards behind the bar, so get a drink on me!

Been trawling this forum for answers, its great! Found many great tips on changing bits and troubleshooting.

So ive recently changed my variator, rollers, belt and cleaned out my clutch bell and clutch with carb cleaner.

All clean and running well. Tops speed has increased and the bike rides well.

However im having issues when riding off, the belt seems to slip for about 5 secs. When i hit the gas at the lights, the bike revs but with little movement, but once it grabs its perfect.

Any ideas? Im sure everything is put back properly, ive changed my belt rollers etc few times before.

Thanks in advance guys

What model bike do you have? What year?

Hey thanks for the response, i have a habana retro 125 20001.

Think its the same engine as the vespa et4, thats what lead me here!

Any ideas? Not sure what else it can be??

Thanks in advance

If your top end has increased then your lower end will decrease,
Can't have both, You can change that though by changing the rollers again.

You may want to lower your top end a bit for a quicker low end.

If you're describing what I think you're describing, then they all do that. It's akin to driving a manual transmission car and slipping the clutch really slowly while giving it too much gas? High rev, then it feels like it grabs and you're off?

If this is what you're describing, then it's normal. It's not like an automatic car where you give it gas and it just responds. There's revving...

No, they all don't do that. My LX bites almost right away. The OP explained that his scooter is different now after the belt service, so he is saying it didn't do that before.

Yeah, but it's purple.

This is hard to explain, so does my GT. But there is a slight revving as the engine and transmission meet to get you going. Plus? You might be a tiny little thing.

I've never been around a scooter with an automagic transmission that doesn't do this. I'm not explaining myself clearly enough, sorry. But they do.

It's Daring Plum and I'm 245. Maybe you have a swishy clutch.

Habanas had the Pre-leader version of the ET4 engine, not the leader that was available in North America.

wow, that's a whole bunch of variables that have been changed.

taking a stab in the dark, i'd say you've got an issue with your clutch shoes or bell. i'd attempt cleaning/deglazing the shoe and/or bell. but you may have a deeper problem than that.

however, considering everything is kosher and the install is proper i'd check your valves. occasionaly you can get a bit of sluggish performance from valves that are out of adjustment.

best,
-greasy

It's not the clutch that's swishy!

Thank you, folks! I'm here all week, try the veal.

Wow this forum is really active! Im quite new to forums, but i can see myself getting hooked! Thanks for all the replies

Well i started to think that maybe it was just me and that i imagined it was quicker off the lights, but i am convinced there is something wrong.

I only noticed it recently after my last belt broke and i replaced it.

Ive checked the clutch and theres plenty of meat on the shoes, sprayed out all the gunk from with carb cleaner etc.

What about my airbox? i fiddled with that when doing the repairs, and when i go over humps i get a clunk noise like something is loose?

When replacing the belt and started up the engine, the belt seemed a bit loose, it had about 2cm of play, is that normal?

I called the aprilia shop and the mechanic didnt have a clue.

Im lost now, maybe i should just get a vespa

Sorry to hijack the thread, but do all of these scooters use belts?
I just care about the Piaggio Fly.

I noticed it acts weird if I'm accelerating down a hill with no throttle, but then engage the throttle. Hearing about this belt thing makes me thing it is just that the engine has to catch it.

Going down hill, maintain a little bit of throttle which will keep the clutch engaged and you will utilize some engine compression to help control speed.

Thanks for the advice, NightWing.