so back in 05 i bought a brand new 05 400ex. i upgraded from a yamaha timberwolf 250 4x4. so when i first started riding it, i thought it had all kinds of power. which it did. 5 years later i traded for a 2005 450r. i love everything about it, except that i miss the functionality of my 400 on the trails VS the 450r. riding the 400 i felt the power was ok but nothing exciting was going on. i had a hot cam stage 1, full pipe, jetted, K&N, open air box. so im curious as to when the time comes which 400 should i buy? i really like how reliable my 400 is. only had to replace two sets of rear wheel bearings, and a battery in the 5 years of owning this machine! im also interested in the z400, mostly because of the upgraded suspension, DOHC, and fuel injection! let me know what everyone thinks.

 

i never rode a 09+ z400, but i have owned an 06 kfx400, 05 z400, and 2 400exs but unfortunetly i didnt have the z400 and 400ex at the same time, but the 400ex i think handles better ad has more low end power. the z and kfx are faster stock, but not by a lot. the z responds better to bolt on mods too. you couldnt go wrong with either

 

Ive only ridden an 03 Z400 and I have a 01 400ex and i perfer it for trail ridding, better low end and it doesnt need to be reved up to keep it from stalling on the tight technical stuff. The 400ex can be bogged down in 1st and 2nd and not have to worry bout stalling all the time. Speen isnt really a factor i care too much about i like the hadling and low end power of the 400ex better.

 

The 09 Z400 with EFI will be a hard bike to beat! Dirt Wheels did a test between it and a Can-Am 450 and a Raptor 700R the Z and the 700 were pretty close tho the 700 was by far the better trail bike but they liked the fact that the Z with a few mods could be a beginner MX bike that and the fact compared to the other two it got much better MPG's. The 09 Z in nothing like the previous Z's and well worth a look!

 

they actually picked the z400 for the win in that shootout and i would too! $8400 for a raptor? i could care less about efi on a sport quad and in the woods the 400ex is still among the best

 

EFI For me is a must as I ride anywhere from 9000 ft to 14000 ft and it make life so much more pleasurable. Wont own another bike without it!

 

A simple sprocket change on the z and it runs much better on the trails.

 

i like that the 400ex follows the K.I.S.S philosopy (keep it simple stupid). yeah efi is nice, but i dont make great changes in altitude. i had the carbed and efi sportsmans out toiday and the efi one is a bit quicker and faster and better on fuel... just hope it never breaks

 

I cant speak for Polaris but the electronics used on Yamaha machines are based off the Yamaha's road bike technology and nock on wood both EFI units I have have been bullet proof so far.

 

If you get the z, are you going to have to change your username?

Since you've had the ex before, why not see what the z is like. At the worst, you could sell it and go back to the ex.