Modern Vespa

Hey guys, so earlier you guys said to get a genuine carborator. So I did. But this one doesn't have a mixture screw? Is this normal? One side has treads but it's blank and the other has no threads and there's a hole at the end. Did I get a bad carborator??

Is the new carb a genuine Dell'Orto PHVA or a clone?

I circled the area where the mixture screw generally belongs. There should be an identical casting on the other side of the carb body; Dell'Orto offers multiple variations on this carb to allow for different fitment applications. It there a screw in the other side?

Generally, the unused side is cast but not drilled through, or it is fitted with an aluminum blanking cap.

I'm including pics of an original PVHA 12 that was fitted to a scoot I bought but was not the original fitment...fairly sure of that because it makes no sense to use a variant that points the idle and mixture screws towards the tire.

Can you share photos that show the Dell'Orto stampings and model info? Would you also include a picture looking down the carburetor throat? I'm wondering if you might have one of those oddball lean–burn variants of that carburetor.

Here's the other side. I hooked it all up and the bike ran for about a minute but when I came to a stop again it died, now it doesn't start again. It turns over and over and over but doesn't start.

Update it starts right up after a minute or 2 of sitting and revs fine and drives fine but it won't idle. It keeps dieing if I let go of the throttle. And once it does it doesn't start again

You're definitely missing the mixture screw. It probably belongs where the threaded hole is. That would be a big air leak.

I dont think so anymore. After some reading California had laws where new carbs can't have mixture screws so you can't mess with the emissions. I found out the problem was a vacuum leak. Now it runs just fine. It does bog down a bit at full throttle though, I'll have to check what that is