150cc benelli andretti 150xt problems, help please.

[Impaired]

OK so I did some routine maintenance on my scooter I changed the spark plug and the fuel filter, both of which have never been replaced after 8k miles (long story)..also I noticed the air box hose to the carbuerator wasn't attached so I attached that.

My problem is after I made the changes the scooter wasn't running very well...
The airbox hose hasn't been off very long maybe a few weeks.
The scooter was running very rich and it would run maybe 1/4 a mile then bog down and shut off, or it would shut off at sudden stops, I tried adjusting the idle screw but it didn't help much unless I had it running so open that the back tire would start spinning on it's own.

Idk which spark plug I used but the online source I used said it was good, if it's the wrong spark plug will that cause these issues?

Or could it be the fuel filter I added is a wrong type (advertised for 150cc scooters) and is allowing too much fuel to the Carb?

Any ideas are greatly appreciated.

Also now the scoot won't start at all no power to any gauges, the ignition switch is brand new and the battery is new so I need to check the fussed yes?
There are 15v(or amp?) Fuses in a box but isn't there a 10v(amp?) Fuse somewhere else also???

Thanks guys, here's a pic of the fuel filter, the arrows indicate how the fuel is supposed to flow through it right?
http://i.imgur.com/FOPriUG.jpg