Modern Vespa

Hey everyone!

I've got a few ideas about what might be causing some of the issues with my GT, but I thought I would run it by the group here first.

Symptoms:

High idle. It gets worse with heat. Turned idle screw nearly all the way out, no effect. The idle is so high that at best it's just below the friction zone, but on a hot day or if it's been running for a while, it'll start to drag the clutch at idle. Since it varies with temp, I'm thinking an air leak that gets worse with heat expansion. If it were the throttle cable, it would be high, but not variable. Also, it used to run fine, and I haven't made any changes since.

My plan is to tighten everything up and see if it helps. Also, could a failed SAS cause this? Performance doesn't change whether I connect or disconnect the SAS tube from the manifold. Could it be a failed autochoke?

Hi Ian,

It does sound like an air leak. Keep us posted so we can learn from your experience.