I want more power out of my ex. I have a fully modded 440. How much would it cost me to put a 426 or a 450 in it. Also what all would I need to do?

 

I'd say hold off for a minute, could you imagine if you put all the time and money into the conversion and next year they produce it!

 

I dont know what your fully modded 440 has, but if it is like I mine it should be at least close to a YZ426. Off the line at a TT race my 440 ran right down the straight with a YZ426 no problem.

If you look at GT Thunder's dynos you will see that fully modded 400EXs are right there with YZ400's. Basically, the YZ426 are awesome stock, but there really isnt anything you can do to them sure they make +40HP, but that is really all they can ever make.

I ride/race with alot of quads and I know my quad has the power to run with almost any of them. Before somebody starts running their mouth remember I did say most of them. I know there are plenty of other big bores that can beat me namely the 330Rs and such.

Adam Smith

99 400EX

 

 

Gotta disagree with ya here Adam.The 440 kit on the EX puts out around 35 HP where a 426 puts 46-50 to the rear wheel and does so in a much faster "2stroke like" manner and cleanly revs much higher.The 426 is head and shoulders a better engine than an XR440.