Modern Vespa

TLDR; does this bellow need to be intact?

So my very-low-miles (2,500 miles on the odometer) 2006 LX 150 has sat in my garage for 4 years (yeah, I know!), so I want to sell it. I replaced the battery and it cranks fine but won't start. The gas gauge shows an empty tank, so I added a few ounces (I know I didn't run it completely out of gas when I put it away for the winter 4 years ago).

From everything I read, it sounds like the carburetor would need a cleaning. I took it apart and was surprised that no gas came out of it! It's very clean and the idle jets still show pure brass, very clean, so no point in cleaning them (photo 1).

In photo #12 here https://modernvespa.com/forum/topic82623, it says to press the accelerator pump to see fuel spray out, so I added a little more gas to the gas tank and pressed the pump and nothing sprayed out. Upon closer inspection, it looks like a rubber bellow has disintegrated where it was attached with a metal clamp (photos 2 & 3).

Looks like part #17 on this page:

https://www.scooterwest.com/vespa-piaggio-150cc-2v-leader-carburetor-2006-2019.html

17 CM140403-BELLOW
CARB ACCELERATOR PUMP RUBBER BELLOW KEIHIN LX150 GT200

... which is this part:

https://www.scooterwest.com/lx-150-float-bowl-cover-kit-2006-2010-lx150-cm140403-1.html

Does this bellow need to be intact for it to work? Could I have a different problem? Is it supposed to have a clamp on it?

I can follow instructions fine, but I'm not really a grease monkey, so don't get too complicated on me Thanks!

Short answer - no, it does not need to be intact to start the scoot. It does need a clean idle jet and a working choke circuit.

The fuel will not flow without vacuum opening the fuel valve. Check the vacuum line for cracks or holes.

That little rubber bellows is a generic part - I replaced mine with one on eBay that was supposedly a Harley part. Not necessary for carb operation, but a good idea to install once you have the carb working again.

Don't put fresh fuel into a gunky tank and hope the carb won"t notice. You need to clean your tank out before you attempt to clean the carb, or the gunk will keep sliding into the carb orifices.