Modern Vespa

Is there any way to adjust the throttle spring tension on a GTV 250? I'm not talking free play in the cables, that's fine. The throttle twists with almost no resistance, vastly different than my LX 150.

This is a safety issue because the lack of resistance on the the throttle combined with the tendency to slip on the nice leather GTV 250 seat has frequently created a problem. When I crack the throttle I begin to slide back in the seat, and with almost no resistance the throttle rolls open more as I slide back. The scoot accelerates more, I slide back more, the throttle opens more ...

I have found I can only really stabilize myself on the 250 using my left hand. The throttle grip twists far too easily for me to use my right hand for much steering input. The throttle takes up a lot of the movement and instead of applying force to the right handlebar for steering I end up mixing in unwanted throttle input.

I've looked at the throttle body and I don't immediately see a spring adjustment but it's mighty tight down there.

This issue almost killed me today In an emergency stop situation the simple friction of my gloved thumb against the throttle grip as I quickly reached for the brakes was enough to twist on the throttle and I was launched into oncoming traffic.

When I got home I immediately ripped into the death trap. I removed the throttle cam from the throttle shaft, rotated the fixed end of the spring 90 degrees counter clockwise, and reassembled the throttle cam with the increased spring tension.

The fixed end of throttle spring was originally held against the throttle body standoff that holds the idle stop. I rotated the spring 90 CCW so that the fixed end of the spring is now held by the upper throttle cable (throttle return cable) attachment standoff. The cam end of the spring is being held by the same stop on the cam.

In the original spring orientation it offered almost no resistance to rolling on. In this new orientation, with 90 degrees of pre-load on the spring, the throttle is far more controllable and drivable. It no longer rolls in response to tiny movements in my hand or handlebar position. The feel is now also nearly identical to my LX 150.

I don't know if the spring is incorrect or defective, or if the spring was initially installed incorrectly, but either way the original condition was deadly. This is on a GTV 250 with only 1600 miles purchased new from the dealer. To my knowledge this spring and throttle cam has never been taken apart. Can anyone tell me how the spring is supposed to be fixed or is the spring possibly incorrect or defective?

You should contact your dealer. It sounds like an issue they should fix, you shouldn't have to void the warranty to save your life. I thought the scooters came with one year unlimited mielage with radside assistance. I would try that and get them to fix it right.

If they won't help you call Piaggio Customer Care.

Good luck and keep us posted.