Is it the fastest dirt bike out? Is it faster than the Yamaha 440cc bike? It should be since its a 2 stroker. Thanks

 

Yes it is monster! It is the fastest stock dirtbike that I know of. Some say they do around 100 mph. That motor mated with a 250R chassis would be insane!!!!

 

Yeah, it is fast, but not the fastest. If your are looking for the most powerful, the KX500 is the ticket. Doesn't handle motocross as well as the others(stock) but the power is just crazy. I used to ride the open class on one of these monsters and just recently gave up racing the bikes because of serious injuries. There is ablolutely nothing that compares to the stock KX, and if you add a little porting and a pipe, just keep 911 on hold. The new XR 650 is pretty fast and powerful, but not quite the mind snapping power of the KX.

 

One really bad @$$ dirt bike is the KTM 520sx!!!!!! I've ridden one and I will admit I am scared to get in 5th gear!!!!

 

The Cr 500 is slightly faster than the KX, and what Yamaha 440??

 

i know a kid that has a '74 kawasaki 100cc dirt enduro that according to him goes 85mph, and he said he was doing it. he said the spedometer said he was going that fast, so he was. i drove it, and it made my trailblazer feel like a sandrail!

 

Buddy of mine has one says it will do 105 - 110 ! That is moving right there

 

I am only going to beat this dead horse this once. The KX500 is the most powerful production motocrosser made, past or present. The CR is probably a better all around unit do to its relatively more modern layout, but for sheer accelleration and power, take a run through the gears on the KX and everything pales in comparison. The 520 seemed pitiful to me, but still a very fast open classer.

 

Ridzhard is right, the KX 500 is the undisputed king of horsepower. It has a power valve and a nickasil coated cylinder while the CR 500 has neither. The KX makes a flat ten horsepower more than the CR 500 - this is common knowledge among motocrossers since neither bike has been changed in ten years except for the graphics and the KX forks which were redone in 96. The CR has a rep as a better handling MX machine while the KX is better at desert racing/XC due to the extra power. The CR is also supposedly more reliable but I never had any trouble with my 97 KX500 which I owned for over a year. Which is fastest is sort of a mute point since either bike is just plain sick fast!

Compared to the new Yamaha 426 both the CR500 and KX500 would smoke it in a drag race but on an MX track the Yamaha would be better. I race 250B right now on a 2000 KX250 and have to race those dang YZ 426's in my class. They are fast and do REALLY well when the track is slick. The only thing I notice about the YZ 400/426 is that every time I am at the gate we have to wait on some guy trying to get his started. More than once I have seen a guy kick till he was blue in the face and just give up and push his bike back to the pits.

 

Yes, the 400YZF (or 426) is a pain to get started.
And yes the KX500 is the scariest thing you can get. No way a KTM520 is more thrilling. Faster? Probably.