my freind has a 96 warrior and when he runs out of gas his reserve doesnt work, but there is gas in the reserve so we towed him to the gas station and he drained the gas out of the reserve then it was realy hard to start and then after that his resevrve doesnt work anymore what could be the problem

 

The reserve gas pick-up at the fuel valve could be clogged. Also, if your engine runs out of gas, and you need to switch to reserve, it takes a few times to get it started up again.

 

drain the tank. unscrew the petcock from the bottom of the tank and clean the sreans on the pickup tubes. hope this works

 

I did some work on a girl's Kaw once. Did all kinds of stuff, then found out the petcock on the tank was full of "mung".
Remove it, scrub it out, I used carb cleaner, that stuff is potent!