I have to admit, I've problem been spoiled by my XR600. Doing the valves couldn't be easier. Screwdriver, feeler, wrench, a little time. I'm this -><- close to buying a 2006 WR450 (possibly a 400EXC...), and I'm trying to get a feel for how often the WR needs to be serviced. For example, how many miles/hours do you go between valve adjustments? How many filters are there and places to drain oil? Is there anything else that needs to be done regularly? Coolant? I guess they don't put the service manuals online to take a look at. It would be interesting to see what I'm getting into before buying. Thanks.