Will a YZ450 Motor work in a YFZ450 frame without modification??

[yz450hybrid]

I was going to build a LSR hybrid, and decided to not go through with it. I have a complete yfz450 rolling chassis that is all setup for xc, but the yfz450 motor needs a new bottom end, so i started thinking that maybe i could use the rebuilt 03 YZ450 dirt bike motor that i have in the YFZ450 frame??

Does anyone know if the mounting is the same and also would the yfz450 exhaust mount right up to the yz motor??

Any help would be appreciated.. thanks

[jrspawn]

will not bolt up without a good bit of modification. I had one of my old laeger yzf hybrids switched over to a YFZ450 engine, there was a good bit of modification done to the frame to make it work correct.

[kyledvor61]

I'm not exactly sure about a 450, but it is different from a 426. Id assume the dirtbike motors to be the same because of the chassis but im not 100% sure.

Anyway, my frame was made for the 426 dirtbike motor and im currently putting in the yfz450 fourwheeler motor. Things ive noticed so far are the swingarm bolts are different. The dirtbike is bigger then the fourwheeler one. I remember reading that the front sprocket is not in the same spot. It's offset to the left or right a little bit. One of the elctrical boxes is smaller and wont fit my mount. I'm pretty sure my front mounts fit but im not 100% sure yet. The bottom mount is the same though.

From what ive noticed so far its obviously not a direct drop in, but its really not that much work if your mechanically inclined.