Modern Vespa

Hello, everyone!

All issues starts after I decided to set up a new air filter and to clean the trottle valve and body. So, after that my bike starts working really unstable. My friend said that I have to "adjust" the throttle after the cleaning. But I don't know how.

I've found only "Zeroing the throttle" paragraph in "Gilera_Fuoco Workshop Manual". But there is a warning in the end of that paragraph: "THE TPS RESETTING POSITION MUST NOT BE CARRIED OUT WITH A USED THROTTLE BODY..."
So, I am still using the same throttle body. That means that I shouldn't do one, am I right?

Any suggestions where can be the problem?

Best suggestion is to go back to the stock factory airfilter.

location ?

and could be that the idle valve is still dirty how did you clean the throttle body ?

Also you won't be able to reset the tps you need special software

I've tried one. It doesn't help. Yeah, I thought the same way. So, I've cleaned it 2 times, but nothing happened.

Thanks for your answers guys!

I'll try to check bike's wires connections. Maybe I accidentally cut or didn't connect some wire, after I've removed/isntalled the throttle body.

Also I've read that after cleaning the "electronic" throttle you must do adjustment reset. Because if you would clean the throttle valve and won't do adjutment reset, your throttle valve would keep openning with correction for dirt that was on your valve. But it was general info for every valve throttle with electronic systems. There was said: "You can try to disconnect your battery for a few minutes to reset the throttle adjustment..."

Maybe I should try that one too

If you tampered with the butterfly valve itself, you may have damaged the mechanical connection from the stepper motor that drives it. Cleaning the throttle body shouldn't ever need any touching of the parts inside.

Well. I am sure that mechanical part is OK. This is not my first time I'm cleaning the throttle valve. The purpose of the stepper motor is to control the idle speed of the engine in all conditions. But my bike works unstable even when I am openning the throttle in mid/full speed. Yeah, you don't need to completely disassemble the whole throttle body. But after a long using of your motorbike, you should check (and clean if needed) the throttle valve. There are some dirt in the air that your thottle body takes. Especially if you're forgetting to clean or change your air filter in time. Also there are some other nuances and stuff. So, the butterfly valve gets dirty over the time anyway. I found some dirt on my valve too. That's why I cleaned it after a new air fliter has been installed.
I will add some examples in the end.

Thanks for your suggestion anyway

Hello again boys! Reporting in!

I've repaired my bike. Everything is fine now. So, me and few of my friends have been sitting in a garage about the whole day doing such things as: removing the thorttle body to check if something is damaged, dismantling control unit to check it and all wires with multimeter. Everything was FINE!
We've put everything back as it was before. The bike still worked unstable.Then the fork stabilization bulb became red! So I've tapped 2 times on stabilization lever at the throttle stick way. The bulb went out. Aaaand.... My bike runs PERFECT now. Everything is fine, like nothing happened.

What was that? No one knows and no one can explain.
Why was that? No one knows and no one can explain.
Everyone still have a lot of questions about that occasion.

Maybe it was some sort of a glitch in the software/electrical "brains" or something.

Thanks everyone who tried to help!

Last edited by Toy_Yota on Tue, 09 May 2023 07:59:46 +0000; edited 2 times

Your own head does the same thing. You can't remember a name or a word, and then 3 hours later it just pops into your mind.

So true!