I own a 1999 Honda 400 ex and this thing just keeps on running!  I ride this thing nearly everyday, keep the fluids changed and the chain lubed and that's about it.  I want to get a new quad,  but my wife won't let me because this one runs so good.  Has anyone had this much luck with there quads?  With the exception of the initial cost,  the only money I have spent was for new grips and regular maintanence.   

My cousin has an '05 TRX400EX, with reverse.  Great quad- built like a tank.  Plenty of torque for me.  

I have a 2001 400ex that is the same way. My dad rode it for 4 years and i have been riding it for about the last year and a half. I've rode it everyday and it still runs real good. i added parts for the fun of it but not because it's needed it. I'm lookin at gettin a new bike too. 400ex's might even be more reliable than the old 300ex's.

Ya i got an 88' Blaster that is still all stock NOTHING mod'd on it at all cept maybe a spark plug upgrade from regular ngk to the more expensive kind to see if there is a change. but i ride that thing almost everyday and it has never once died on me or even ran badly untile lately i messed with the carb and the engines kinda getting messed up but ya its way awesome. It just keeps runnin