Motorcycles, Snowmobiles, Go-Carts, ATV's and Golf Carts - Gas Scooter won't start

I have a small 2 stroke gas scooter, something to just play around with. A few days ago, I tried to increase the amount of air coming in the intake to try to give it a little more power. I took off the plastic covering on the carb (I think that's what it's called... I really don't know a lot about motors). After this, I decided it would be a smart idea to take the muffler off which at the time, I did not know this was a "no-no". After I rode it for maybe 3 minutes, I parked it and put everything back on and in its place. When I tried to start it again, it wouldn't for the life of me start back. I also replaced the spark plug, but I'm thinking maybe there was a problem with the spark plug wire. When you pull on the start cord isn't the plug supposed to spark? I unhooked it and didn't see anything when I pulled the start cord. I'm hoping I haven't completely killed it and maybe it will be something easy I'm overlooking. Thanks.

Probably didn't kill anything in 3 minutes, but it's hard to say what would suddenly show up. Checking the spark was a good idea, but you have to ground the plug to the engine (the best place since it's handy and close to where the plug usually goes). Check it in the dark = closed garage or in the evening. It's easier then. Should be a blue spark - not yellow.

If no spark, post back with the year and model/make and we'll try to scare up something on the problem.