This week we scoped a Yamaha YFZ450 with some decent mods and an affordable $2300 price tag:

Weekly Used ATV Deal: Clean YFZ450 in Texas - ATVConnection.com

 

Good price though I always cringe a bit when I see a quad like this with a modified engine. Even if it wasn't ran hard(which is doubtful) modified engines are never as reliable as stock. I'd rather find one that was bone stock, not even an aftermarket exhaust. Added protection like nerf bars and skid plates would be nice though.

 

That wouldn't bother me as much. From experience, Yamaha has one of the stoutest 450 engines on the market. I question the hot cam, the stock cams are actually hard to beat on these power wise, and the stock cams are gentler on the valves than aftermarket as well usually. If they are built with quality parts, they are close to stock reliability as it is in a good state of tune from the factory. Most of what we can do is add fuel and air.