Talk:Yamaha YZ450F

message: "In 1996, the AMA changed racing rules to allow 450cc four strokes to compete in the same racing class as 250cc two strokes"
wrong? someone correct me otherwise, but yamaha developed a 400cc bike, not 450, and later in the article about the 450 there is a mention of new rules.... also, reference is to the 2006 rulebook, not the '96 one. note the ten year difference. Motorbyclist 03:48, 20 May 2007 (UTC)
replies: text: I don't know the full ins and outs of the history but IIRC the FIM (and presumably the AMA) at some point around the YZ400F created the 4504T is euqal to a 2502T rule for MX (ie you could run them in the same class, previsouly it was 250cc 2t ***AND*** 4t). the YZ fourstroke went through development, wiht the YZ426F coming out the next year, followed ever since by the YZ450F and other manufactres 450cc's. One presumes the reference to the rule book is the standard table that shows what cc's are for which class (eg in the states the "motocross" class is probably 275cc 4T up to 450cc 4T and 175cc 2T up to 250cc 2T). Pickle 09:53, 20 May 2007 (UTC)
replies: text: Yeah, that was a mistake on my part. Yamaha did develop the YZ400F first, not the 450. The rule was actually instated with a 520cc limit on four-strokes, but for 2002, the displacement limit was lowerd to 450cc's. I know this for a fact, but it's difficult to find a reputable online source for this. Any suggestions as to how to incorporate this into the article? Barang 19:29, 20 May 2007 (UTC)

message: If the YZ400F, YZ426F and YZ450F are all pointing to this page, should it not be renamed to something more apppropriate such as "Yamaha's big cc fourstroke motorbike" or something ??? Pickle 00:55, 23 May 2007 (UTC)
thread_title:  Article name 

message: Attention yamaha MX experts, owners, etc - Is this a YZ450F or YZ250F ??? - thanks in advance Pickle 11:42, 23 September 2007 (UTC)
replies: text: If it helps I uploaded another shot of the same (pretty sure) bike and rider taken without motion blur --Fir0002 00:03, 24 September 2007 (UTC)
replies: text:  Cheers Fir0002, all i can read is "GYTR" which on googling with yamaha dosne't bring up much (some sort of factory extra). I'm hoping a yamaha and/or MX expert will be able to fill us in ;) Pickle 20:53, 25 September 2007 (UTC)
replies: text:  It doesn't matter, using this picture for either 2008/2009 model would be acceptable. The bikes are virtually identical from outward appearances. The only visible difference is the size of the rear tire. Based on that I would guess this is a 250. I ♥ ♪ ♫(talk) 03:59, 25 March 2011 (UTC)
thread_title:  phoot ID 

message: I don't believe an aluminum frame (pretty much an industry standard item) or returning to a 5-speed transmission constitutes a fourth generation for the YZ450. All bikes change all the time. The YZ400 is clearly generation one, YZ426 clearly generation two, but 2003 through 2009 is the same bike despite the marketing hype. The first lines of the generation 4 & 5 sections summarize it succinctly, "the biggest update" vs. "Yamaha introduced its all new". Not until 2010 is there a significant difference in the YZ450. The fuel injected rear facing engine dictates generational changes such as the intake in front of the bike, the exhaust coming out the back side of the cylinder and the tank located under the seat. These are truly generational if not revolutionary differences. I suggest combining gens. 3&4, particularly since the section on gen. 4 is tagged as too brief. Another indicator that there has been a generational shift is the fact that the Yamaha WR450F still uses the gen. 3 motor in 2011. I ♥ ♪ ♫(talk) 03:03, 25 March 2011 (UTC)
thread_title:  Iterations not Generational