i know this is a old thread but i have a 400 and i love mine and the guy in the link looks like hes racing a z400 ds650 400ex and a raptor i dont know what the guy did to his ex but it whoops everyone http://www.killeratv.com/Videos/Sport/400EX%20Smokin'em.mpg

 

i would definately go big bore with the 400ex, get the 440 kit. my friend has a 416ex and it keeps right up with a piped jetted predator, and a predator is on par with a 660 raptor.

 

all i can say is with my 440 kit with a 11:1 piston and oversize head studs, i cant keep a head gasket in it for more than a week, others can run forever on 440, some i guess arnt as lucky as others, but when it is runnin good with all the mods i have, it runs really strong, and will keep up with 660's and stock 450's but who has a stock 450 anymore....

Wreckless

 

I have 400Ex that I have put through some major terain and my buddies who have Suzukis and Can Ams always seem to break and I haven't yet.

 

As for the subject of this thread, if you have the option to buy the 450r, buy it, because you'll never keep up with the other machines you listed without spending money in the 5-digit range. Notice the 450"R" as-in "racing"? Certain quads tend to be designed for certain riding conditions and terrains in mind.

But seriously though, am I the only one here who is more into having fun and not just beating other people? The only thing I ever see on this forum is people trying to figure out whose quad will beat whose. Why is it never a discussion of which quads have better handling, agility, lower weight, better reliability, higher build quality, ease of starting, maintenance requirements and scheduling, longer lifetime, more convenience, and better price? And how is it that no one ever talks about the tires they are using (weight, ideal tread, remaining tread, diameter, materials) on the type of terrain they are "trying to beat" someone else on? I'd like as many people to reply to me as they can, I'm really interested in seeing what other opinions are present.

 

<div class="FTQUOTE"><begin quote>Originally posted by: dunefool

I would keep it stock and save for a 450. You will end up nickle and diming it and wishing you had more power most likely. 440 kits on 400ex's have the tendency of blowing head gaskets out. Just my 2 cents.</end quote></div>


^^^^^

Speaks the truth.

 

13.1 flat stock size piston,mill head,stage2 cam,port&polish,crf450 time chain,carb jet kit 170m/45p and drill out choke,k&n,pipe,gears, and some race fuel