Get whatever quad feels better. They are so similar when it comes to performance. The Honda however is cheaper (4899.00 where I live), and stronger built. I Have a friend that owns a KFX400 that bent both tie rods within two months, the stock air filter is junk, the stock skid plate is plastic, and is a pain to even rejet the carb. These may sound minor, but it's the little things that add up. We both have the same pipe, both have rejetted, and have the same air filter and he can't beat me. As far as the weight goes, who cares it's not that big of a difference.

Yes I am Honda loyal, but facts are facts.

 

Oh ya! the Z is water cooled, BIG DEAL. I have never had an issue. I ride in 90 - 100 degree temps all the time.

 

you woudn't have to mod the Z if all you wanted to do was beat an ex........you will have NO problem if they are both stock..........
the Z is MUCH quicker in a drag race!!!!

 

This is such crap. The speeds are so identical, it all depends on the rider.

 

Nice used Z, around $4500, hard to find.

Nice used EX, $3000, easy to find.

 

the z has a little more performance stock for stock....but right now ex's are gonna be going for cheap, real cheap, you could get a modded one for a good price, or stock and use the money you saved to mod it to your specs.
just my .02

 

As for the things you stated to do with these atvs both will do very close to the same. If you are trying to pick between wich one to buy the right choice is the Z400. You have to think about this, the technology is much more advanced on the Z400, they are 2 different stages in the ATV history. I think buying any aircooled sport quad is a waist of money right now since the new era is liquid cooled.

 

Water cooled is overated it's a sales pitch. This does not add to the performance of the quad and it's just another thing to worry about. Pick the quad you like better (wich one feels better etc.) and go with that

 

exactly, just because its the new era, doesnt mean its what you HAVE to do.
Liquid cooling doesnt neccessarily add hp, you may run at peak longer, but thats it. Its also something that can go wrong, pumps, hoses, etc.