Modern Vespa

Just received a "Stop & Go" ATV Tire repair kit for my scoot. Cost $19.99+,ship versus the standard repair kit at $49. Here is what is included in the ATV Kit......2 CO2 canisters, 16 grams each, 3 inch flexible vinyl adapter with brass fittings, Split-Eye needle insertion tool, Rasp tool, tube Rubber Cement,
5..4 1/2 inch Rubber plugs. Any idea how many canisters are used on one
scooter tire fix for on the road travel?

for the size of a scooter tire 1 can should do.

If your tire is completely flat, 1 can will not be sufficient. Stop & Go claims the 16 gram canisters will each generate 9 lbs of pressure. In my motorcycle kit it specifically recommends 3 canisters for a front tire or 4 for a rear tire. Again, this assumes you have practically no pressure left. If you carry a pressure gauge you can double check after you add each can.

for m/c tires yes more than 1 can as the tires have a lot more volume inside to fill than a small scooter tire.

If they think two cans will fill an ATV tire, I would tend to disagree but for that price you can get more canisters at your local sporting goods or bike shop. I know REI sells them bulk (no packaging). I would want more than 2.