Another way to look at this...Let's compare a 2003 Mach Z to a 2003 RX-1, both with 20 000 km's. Or, we'll continue this discussion in 2009 (comparing a 2006 Mach and a 2006 Apex). In my opinion, a large, twin cylinder two stroke in a stamped aluminum chassis is a disposable toy, probably rated for 300-400 hours. Although I cannot find a quote from any Yamaha engineers, I would imagine the RX-1 was designed for closer to 1000 hours. Translation: Live fast, die young. (Not you, Skidoo10setsofrings.)