It's not a YFZ but there is a huge difference in price and with that varience you can go a long way with Z. I've found the Z's out the door now for $4895 compare that to the YFZ best deals at $6995 OTD.
ok...lets add it up
Z400: 4900 + tax
Frame: around 2000 (the YFZ chassis is much closer to that of an R frame in size and ergonomics...and the Z's crack). Yhe YFZ is smaller and sits lower than the Z.
Front Shocks: 1000 (the stock Z fronts I wouldn't put on a lawnmower...the YFZ's fronts are supposedly better than Works Pro Series)
External Engine Mods: 350 (with a cheap but excellent slipon such as HMF, filter setup, and jets).
450 Yoshi kit: 2000 (may be 1700)
Carb: 450
Axle: 450
Now that is 9150....and just to be "YFZ-like"
Roberts Sports center sells YFZ's for 6595 + applicable tax out the door.
This would leave the YFZ owner $2555 for mods.
Face it...the Z's had thier year...they are a great quad for trails and such. But for a racer..the YFZ is much wiser choice. Even if ya had the Z's frame gusseted (to fix cracking problem) they still would be at huge disadvantage on track because of the YFZ's more R like handling and ride. Sure...if ya had blasters and 300ex's...a Z feels fast...but if ya had something REALLY fast...the Z is fun....but not real fast.