Well if this is the case, I think the YFZ is a lost cause... The YFZ450 is a great quad, however I don't think you will ever see 100hp out of one. And even if it were possible, I wouldn't want it between my legs!

 

i think they're probably running sleeper 523cc kits.

 

i would say the motor pool in quads is kinda small. if you've reached the limit, outsource a motor from somewhere else. i put this in another raptor guys thread, so u might have seen it. But i've heard KTM 525 motors in raptors, aside form shedding alot of weight, really bump up the power. a guy told me he raced a trx and a yfz at the same time with his 525 hybrid raptor and he had the power to play with them, as in get away from them, slow down, wait for them to catch up, then blow away from them again.

also, a modern cr500 motor would be very powerful, and again very light.

the ultimate i would say would be getting an ATK 700cc 2-stroke motor. they put them in their "intimidator" dirtbikes. but you can get just the motor from an atk dealer for about 3k. i beleive they make 65hp, and are at a mild state of tune for reliability issues. easily making 85+ with porting and such.

lastly, a street bike motor, tho alot of work to put in the chasis, would absouluty blow away ur banshee friends. at the smallest, a 600cc sportbike motor would make 110hp at the wheels. a 1000cc motor or hayabusa will make 150hp at the wheels (with the hayabusa makeing more torque and hp throughout the rev range). I saw a hayabusa powered raptor, and it was awesome looking. if i can find it again i'll post the link. cool thing is u can always turbo charge these further. i've seen turbo hayabusas hit the 600hp range, and the least powerful turboed ones hitting atleast 250hp. skys the limit really if u look to elsewhere for a motor.

i'll try to find the pictures of that hayabusa raptor.

 

I'm just so torn here! I love the YFZ450. I ride my friends all the time at a small supercross track and, i can nail doubles and, triples that i wouldn't even try on my Heavy Weight Raptor and, my friends don't bother on their Shee's! The 450 just seems to have so much versitility and, control. I'm also an old 2 stroke nut - the 450 seems to rev more like a 2 stroke than my Raptor! I know that i'll never get 100 HP out of the 450 but, the ones that can give my banshee buddies a good run till the end are not near that (maybe 60?). Not sure what they have done but, i'd asume (besides bolt-ons) good porting - and, they are able to hang with the fastest "non-Drag" quads!

The Banshee for a pure drag racer and, Dune Screamer is hard to pass up too. The hard hit of the 2 stroke is as addicting as anything i've encountered and, endless fun. Sadly the suspension and, pretty much everything but the motor on the Shee is LAME!

I guess the bottom line is I want to know what i can do and, how much it would be (as in HP and, $) to get the max out of the 450. It seems 60 or so HP 450's are keeping up with the 80+HP Banshees my buddies have. If i can get a 450 to keep up with them I'd be in heaven = I'll have the versitility to do any form of riding real well and, be a contender at the strip! If this is not possible, I guess i have to get a banshee!?!?!?

Can a 450 be made to do it?? For instance - what are some dyno estimates for a 06 YFZ450 with pipe, jetting, pro flo filter, cam mod and, Porting? What else can I do besides bore?

 

well, incase u feel like building a crazy 500cc 2-stroke quad here's where u can find a motor. http://www.servicehonda.com/parts/engines.html scroll thru them motors.

 

or hell, u can get the whole dam bike. can u ride 2 wheels? lol http://www.servicehonda.com/cr500af05.html