YFZ450 or YFZ450R EFI


Can someone please tell me what if any differences are between these engines. I here that its totally different from the bore and stroke, cylinder head, crank, even tranny?:bonk:

Not sure on the transmission, but there is nothing shared with the new "R" engine from the regular YFZ.

the head is from the yz dirtbike

Thanks for the info

Transmission is different, too ( different gears, shafts, and bearings). The R's can be modded to go fast but it's cheaper to hop up a standard YFZ. No comparison on the suspension though. I was beating the snot out of my friends R and it rides and handles quite a bit better than my 06 yfz.

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