Cutaway pic of YFZ 450 motor

[GETSOME]

Finally, dirt bike technology in a quad with no corners cut. I can't wait to throw my legs over yamaha's new quad!

[sly400ex]

Are there any HP ratings on the motor yet????:confused2

[GETSOME]

Can't find any HP numbers from a reliable sourse. I believe both the crf450 and the yz450f make between 45 and 48hp. The new yamaha quad uses the bottom end and gearing from the WR motorcycle for the electric start and all. The WR crank has a slightly shorter stroke than the yz450f rusulting in the 439cc displacement. Thats 11cc's less or 2.4% less cc... So...

100%-2.4% = 97.6%

48hp x 0.976 = 46.8hp

45hp x 0.976 = 43.9hp

That at least gives you a possible range of between 43 and 47hp.

[airheadedduner]

I doubt it makes over 40hp. I remeber seeing someting on a pro built yzf quad and they were getting low to mid 40's with it. Stock, yammy probly corked it a little. I would bet you would see huge gains from just a pipe though. That thing probly won't need much as far as mods.

[F-16Guy]

Yamaha also put a throttle stop and exhaust restrictor (or was it intake?) on the WR bike. I'd look for those on the quad.

[JLanphear]

Take a closer look...I'm not sure of the lifespan of these engines...I've had similar ones in the past and they didn't last very long ;)

[UglyMotha™]

those numbers would be for the dirtbike i'm willing to bet with it setting in the quad frame you only goin to see the motor putting either 38-40 horse down to the ground

[UglyMotha™]

Originally posted by JLanphear
Take a closer look...I'm not sure of the lifespan of these engines...I've had similar ones in the past and they didn't last very long ;)


LMGDAO, now thats funny:p

I know a guy that ain't right that'd prolly pay good monie for that. The pet store in town done cut him off.

[Mxbubs]

That freaking hilarious.


I hope they put bearings around the cam so they cams arent riding in shim buckets like the rest of the YZ motors,and the old honda 350x motor.

[UglyMotha™]

Originally posted by froggigginmama
I know a guy that ain't right that'd prolly pay good monie for that. The pet store in town done cut him off.



why does your buddy like to go gerbiling :huh

[JLanphear]

Originally posted by froggigginmama
I know a guy that ain't right that'd prolly pay good monie for that. The pet store in town done cut him off.

LOL, now that's just sick :eek:

[GETSOME]

that is one tough gerbil to be able to spin a DOHC motor!

[infantry317]

ROTFLMFAO! :D

[spliffy]

Tooooo funny with the gerbil pic LMFAO

[RoadkillerRyan]

Originally posted by JLanphear
Take a closer look...I'm not sure of the lifespan of these engines...I've had similar ones in the past and they didn't last very long ;)


you get him outta there or im calling your mama

[lil400exman]

i always thought they were high revving:confused2

[F-16Guy]

I heard that Richard Geere is one of Yamaha's test riders.:eek2:

[TheRedRebel17]

so thats what stinks in my motor :scary: