well, after the bike sat and a new spark plug was put in, the bike started again and ran. Then my cousin parked it after riding it some, and there was gas leaking out on the floor under it, so maybe the whole issue is a leaking fuel line?

 

Well, after my cousins bike was leaking some fuel, and when it ran it didn't have full power (additionally, he was able to run the bike for about 15 minutes with the fuel dial turned off before it stalled out, kind of weird), I was finally able to get down to help him with it. I tore it apart and took the carb off the bike to check it out. When we opened the carb, and took the top off the vacuum valve, it turns out the vacuum valve spring that is suppose to hold the needle jet down was not in place and was just wrapped around in the vacuum valve. So, we took the carb apart, cleaned it up (not really that dirt or tarnished), blew out all the jets, put it all back together, this time ensuring the spring was correctly installed, and put the bike back together and it started up and seems to run good now. It idled well and didn't stall out for the five minutes I let it run, and then seemed to go good with full power during a 10 minute test ride, so I am thinking that spring wasn't allowing the needle jet to go back down into place and it wasn't getting the proper amount of fuel in the carb and it was screwing it up.

When my cousin go the bike last summer (summer of 2014), the bike had 400 miles on it (and it's an '06). So, I am guessing someone had the bike in a barn for years without running it, and when they decided to sell it, took it apart and cleaned the carb and the jets and everything to get it running and didn't install the spring correctly when they put it back together. I am not sure how it's ran for a 1,000 miles like that and is only now giving him problems, but for the time being it seems to be fixed.

Anyone ever ran into a problem like this before?

Thanks for the input everyone!