Modern Vespa

My windshield is holding up, but a moderate touch in forward (from the seat) gets it very loose and almost falling out. The two large metal bolts that connect it are not sitting in well. I did hammer them in when I installed it.

Not sure what to do

(Non-helpful reply)

Duct Tape?!

Having taken the windshield off and replaced it several times, I am having some difficulty visualizing what bolts required "hammering in" when installing the windshield. The large metal bolts/support bars on my 250 slide into the receiving holes fairly easily and then tightened up using a wrench to tighten the expansion. You may have an entirely different mounting mechanism.

Perhaps a picture would help.

My metal bolts / bars needed a little convincing to seat fully. I used a mallet, which sounds what the OP is describing. The dealer had advised me this was normal, and the instructions that came with the windshield said the same. I have an LX 150, but it sounds similar to me.

I would suggest you remove and reinsert the expansion bolts. Sounds like they were not all the way in the tubes when the bolts were tightened. (I have found that it is sometimes necessary to tap the bolts with a wooden mallet when removing to get the expansion pieces to separate so that the entire expansion bolt comes out together)

You don't hammer them in. You push them in and then tighten them so they expand to fit the hole.

Not to argue but it can take a light "pop" with a soft faced or deadblow mallet to make them seat.
Call it hammering or not mine needed some persuasion or the "shock" of the blow to get them seated properly.

If it is loose then there is only one reason, the bolts are not fully seated as suggested.
You should be able to push them in with your hand. Then tighten them evenly.
If it is still loose then the expansion bolts are kaput, depending on the brand there are hardware replacement kits you can get.

While the principle is the same for all windshields, which company made yours? They all are a little bit different. IIRC, Faco suggests a "tap", Cuppini and Vespa OEM don't.

Well just as I was making a turn today the bolt for windshield in one side got loose and left the housing, it somehow locked the steering wheel (at least in one direction) and down I went...

I was in luck as that was at <5mph in the parking lot...

I think the bolts did not fully expand in the housing as some suggested. I had tape so I temporarily was able to hold them. Later, I hammered them in more aggressively then I turned the bolts with the hex tool all the way until it could turn no more, and now they feel very secure.

Sorry to hear about the spill. The windshield sounds like a Faco -- they do require some "persuasion" to seat properly. Glad to hear everything is now OK.

Yeah too bad about dropping the scoot. Hopefully any damage was minimal .