the dealer says the new 06 will be alot faster then the 05 because of the extra 10 cc but im not so sure. the 05 is 11.9 to 1 and the 06 is only 9.4 to 1. i wonder if the lower compression on the 06 even though it 10 cc longer will just equal it out to the 05.

 

I really don't think it would make such a difference, as you mention they changed the compression, that about equals it out.

 

the 06 is faster the reason why the comp is lower is becuase the larger the cc the less compresion and also becuase if they kept the compresion the same you would have to run race fuel

 

They made more changes than just the 10 extra cc's, and the lower compression ratio. The intake ports are smaller, which increased air intake velocity, and that is supposed to help. They also changed the CDI. So who besides Yamaha knows which is going to be faster? I would bet the '06 model is just slightly faster than an '05 model.

 

im sure it wont be dramatically faster but you may feel something

 

It probably won't be much faster, but the power will be alot smoother

 

its down to 11:4.1 not 9

 

they did over 80 changes to the 06 yfz compared to the 05 yfz.all new cylinder head with revised porting and also a newer 39mm fcr carb.the ignition is also redone for more power for the 06...06 might not blow the 05 out of the water but their will be a differance.its all rider when it comes down to it anyway

 

i totaly agree i am going to try and get an 06 some time this month or two

 

If yall want to know everything that changed on the 06 YFZ450 pick up the August edition of dirt wheels. the yfz is one of the features. There is alot that has changed on the 06.