Did you drain the carb while the bike was stored? If not, you're going to have to pull it and give it a thorough cleaning. If there was gas in the tank over that time, you'll want to drain it and put fresh in as well. Once gas goes bad, no additive is going to bring it back...supposed to treat it before you let it sit with a product like Stabil.

As for the rust in the tank, if you go with that kit (or any similar reline/seal kit), be sure to do a few things first...

1. Remove everything from the tank, including the petcock, fuel level sensor, etc.

2. Get a 2-3 feet length of chain from the local hardware (small enough in diameter to get into the tank through the fill hole), put it in the tank and roll the tank around in your hands. This will help remove any loose rust particles in the tank before you reline/seal it. You don't want to violently shake the tank with the chain in it as you could risk denting it from the inside out. Flush the tank real well with water afterward, let it air out a day or two, then apply the reline/seal kit per the instructions.