Modern Vespa

Have had my lx150 off the road for several years as I got a 65 Allstate.

Pulled engine and changed belt , installed a malossi variator and upgraded secondary gear.

No changes to carb.

Bike has previously had evap removal and new gas and vacuum lines.

Trying to start now but it wont idle, just dies if throttle closed.

New battery.
Added new gas to tank(I cant recall if I added fuel stabilizer to gas that was still in it)
Added Seafoam to clean carb out.

Wouldn't start until I sprayed brake clean into carb while turning it over.

Will start now after a couple tries but fires and dies.

If I can give throttle it runs.

As soon as I release throttle it dies.

Thoughts?

I am thinking carb needs to come out and get cleaned, plus drain all gas and get new.

Correct, clean the carb. Drain the tank.

I'd throw a new fuel tap at it. Probably needs an air filter. Check in intake manifold for cracks.

my intake manifold is brand new. Will do the rest

forgot to add, throw some new fuel and vacuum lines at it while you're there. if they're not deteriorating now, they probably will shortly with fresh fuel and some heat cycles.

good luck!

I will add, if you have access to a sonic cleaner for the carb, try that too. Spray carb cleaner around doesn't always work. That and it's a bitch if you get it in your eyes.