or maybe it was june

 

Good one. I hope your either joking or simply confused. If the crank was changed to shorten the stroke or they went with a shorter connecting rod, the effects will be at both the top and bottom end of the stroke.

One other note (not to you Riznaptor), the motor is based off the WR450, not the YZ from what I've read. I am guessing they did this for the extra torque to help lug the extra weight around vs the YZ.

 

The only thing that changes stroke is the crank!It doesn't matter how long the rod is the stroke will be the same until you change the crank throw.You can have a 350 chevy with long rods and it is still 350ci.It only changes the rod angle

 

dsguru,

I thought about that after I posted. I was on my lunch break at the time and didn't have time to correct myself. But thanks for posting.

 

bad bear is right,yamaha said by the time they changed it to 450cc it was too late in development for them to raise it back up[ to 450

 

I know that the crank is the only thing that changes the stroke. The yz has more compression b/c of the longer stroke is what I am saying. I figure the used that same length rod and used a piston with a long compression height, but without seeing the specs who knows.

 

Ridley,

I stand corrected. I thought that the gearing was a wider ratio (hence the "WR") along with a heavier flywheel.

 

Sounds like the second year quad will be different (now that the rules have changed???)

 

I hope that Yamaha pumps up the 450 to 449 for next year! that would be really nice and plus I would be surprised. The yamaha said that you will still love the power of 439cc.
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Happy Riding,
Dusty