My buddies have 2004 warriors, One had his the first week and it blew up, the other has had engine problems, the yamaha shop told him since his gas tank is plastic the condensation is leaking into his gas so they told him to put heet in it, and it will start but when he goes to give it gas it bogs out. They finally found a problem and said it was the throttle cable and his shop is in the shop on a average once a week for differnt things.

 

My buddy has a 400ex. It is constantly in the shop and warriors blow it away.

 

I have a 2004 Warrior and it runs great, I haven't had any problems.

 

I've got a 2001.

No problems. They're usually pretty bullet-proof.