Do me a favor, use your vast knowledge and compare the 450EXC to the WR450, these are not MX bikes. And by the way, your YZ450 is about 6 HP short of a KTM525SX, so I’m not sure what you’re smoking, but have fun with it.
I ride mostly single track these days and ride with buddies on WR450’s, the power delivery difference between the EXC and the WR450 are very noticeable. I can easily pull away from them at any speed short of top end, and then it’s a dead even pace.
The YFZ 4 wheeler uses the WR450 set up, not the YZF450.
I did not call you simple minded, but if you believe the hype, then maybe you are, good luck with it either way.
Also Mike Lafferty has won several national Enduro titles on the 450EXC competing against every thing Yamaha makes, so i'm guessing its a decent running bike.

 

lets see a pict of your 450exc and show me where to look up the 6hp difference u speak of.

 

I own both and I can tell you the YFZ450 and Z400 shouldn't even be compaired. Even if you do pipe and jet it. THe YFZ is that fast. I love our Z400 but you'd need binoculars if the race goes more than 300 feet.... And just forget about all the pro level comparisons. THey would kill most of us on an LT80.....
jarsong

 

He is speaking of the 525SX versus the 426F not the 450EXC!!! The YZ426F destroyed the KTM on the track and I can only imagine what the 450F would do to it now!

 

I do not own a KTM 525SX, I own a KTM 450EXC. In the KTM line the SX's are the MX bikes and the EXC's are Enduro bikes.
One of the mags just did dyno's on all the 250 class MXers. The 450SX made 2 more horse then the YZ450 and the larger 525SX makes easily 4 more horse then the 450SX.
I do not have the Mag in front of me right now but I think the 450sx was right around 53 on there dyno sheet. It made the most power in the class. They did not dyno the 525SX in that test because it’s an open class bike, not a 250 class bike, but it easily makes 4 more horse then the 450SX.
Give me your e-mail address. I'll take a picture of my toy collection when I get home tonight and e-mail it to you.

 

Yeah a Stock Z400 and YFZ arent comparable But .. I also own both of them and i can tell you that when i had my 03 Z ( SIG v ) I was always about 3-5 bike lengths ahead of the yfz but i ran race gas also and had a load of cash dumped into the engine and suspension. I'm getting ready to get the yoshi kit on my new Z because a friend of mine can easily out run me on my yfz with his yoshi kit on the hills and just about anywhere else exept the mx track. but i love the yfz and wouldn't have anything changed on it ( with the exeption of the hard seat ).

 

YFZinsanity....what happenned too your YFZ too need a new motor?

 

Yunno your about the 200th person that has asked me that.... but its cool ..

Truth is .. don't know it would run fine when you first started it but after it warmed up it wouldn't idle and had absolutely no power then after about 15-20 minutes it would overheat and die and not start again for 20-30 minutes and after it cooled off a little and you tried to crank it over it seemed like it was locking up ( like an old ford with a slow starter ) . after if finally started it just repeated the whole phase like a cycle ( This all started happening right around 35-40 hours on the machine ) .... so beats me.

Our mechanic tore the engine down the first time and ended up replacing the radiator and hoses flushing all of the fluids completly and checked the piston,rings,crank,cam,valves,head and said that pretty much everything was normal .. he even reversed reset the timing back to stock spec and changed my pipe and reset the jetting and it did the same thing. after about a month of this i got pissed and took it back and demanded my money back ( i work for the dealership so that didn't go to well ) .. they took it back into the shop and had it inspected again and then let it set around for a few weeks and then came back to me and said that i couldn't get refunded for it that they would have to replace the parts on it and thats exactly what they did.

We are still waiting to hear from yamaha as to what caused the problem ... so that i couldnt tell ya however i am glad to report that i have racked up around 70-80 hours on the new engine and have not had anything go wrong and hopefully i will not have to report another problem for a long long time

 

your so right my 440 dident smoke anyone its so slow bartlet you are the biggest basher of z400s and its pathetic Im telling you and 2 of the 4 450s that I raced and won against are on this forum 1 is dsracer666 he reces with me and his dad owns the yfz that I beat. Well you dont have to belive it but its true I know you hate the z and the frames and claim they are a pile of junk like you have posted in all of your over openiated postes that you have replied when ever I speak you know it all and if you dont belive it ask tellico he also knows everything. The point is that when built rigth these two bike can compete and I sell all four honda, kawasaki, suzuki and yamaha. Ive riden them ive raced them and have the first hand experiance with them. Im not saying the z is the only quad its just the one for me and with proper mods yes indeed it can be faster then the 450 and 1 of the 4 that I raced had the pipe air box lid removed and the cam in it and yes I sure did beat him not by a mile but it was feet so belive me or dont I dont care im just posting my own openion. there will always be someone faster I really dont have a hard time realizing that but I think some of you do. So flame me if you want but what I saw is what I said. and out of the 6 yfzs that have left our shop 3 have sucessfully blown up so your wonder quad is nothing but a wonder good luck.

 

( z838mx )- out of the 6 yfzs that have left our shop 3 have sucessfully blown up so your wonder quad is nothing but a wonder good luck.

Gee thanks !!! someone could have warned me ...lol just kidding guys i work for a yama-kawi-zuki dealership also .. however i haven't seen any come back in yet ( cept mine [img]i/expressions/face-icon-small-sad.gif[/img] )