My dealer has 2 left-over '04 YZ450F on the floor, brand-new. One has an FMF "silencer", Tag bars, Tag upper clamp. The other is stock. Price is excellent. I currently have a KX125, KTM200sx, and KDX200, all of which are for sale and if they sell, I'm tempted on the YZ450F. I need your advice, though... Me: 44, 170 lbs, 30 yrs experience, don't race (maybe once a year in a 2 hr MX-oriented hare scramble), mostly play-race at the local track, also ride "off-road" in everything from desert to woods. The KTM covers all this ground really well, as did the combination of KDX/KX. The KTM is fairly new to me, though, and I'm not confident of its reliability- right now it has the well-known crankcase crack (from the previous owner's too-tight chain), the fork seals leak, and the front brake gets mushy mid-week. Other than that, this bike is just about perfect for me. I ride 2-3x a week and reliability is extremely high on my list. I don't mind doing pre-maintenance, but I hate having a bike break down. A brand-new Yamaha is appealing and I was looking square at a pre-mix YZ250 until I saw the nearly $1000 cheaper price on the 450F. I'm wondering: 1) the real-life reliability of the YZ450F. Seems good/excellent from what I've read here and elsewhere. 2) will the 450F be too much bike? I've ridden a YZ426 and an RMZ450. The YZ was poorly maintained and I wasn't comfortable with the bent bars and extremely stiff clutch. I was instantly comfortable on the RMZ and it didn't feel like "too much power" at all to me. In fact, I had to look back a couple of times to make sure I was even roosting, it was so smooth. Also ridden a YZ250F and it seemed like the perfect XR to me (I've ridden XR200 and 250's for years)- no scary at all. 3) maintenance costs of the YZ450F. The great thing about the KDX200 and KX125 are that they're relatively easy on the chain/sprocket, tires, and clutch. The YZ450F has got to be harder on these items. Correct? This is a fairly big decision for me. I'm not rich by any means, have 3 kids to support, and am self-employed (meaning: I get hurt, I don't have income). I would expect to run a new bike, whether 250 or 450F, for 4-5 years. What do you think- would a new '04 YZ450F be a good move or should I stick with the KTM200sx? Appreciate any thoughts, comments, warnings, admonishments, rebukes, or pats on the back for those of you who've been there/done that.