Just bought 2004 yz450, need help with mods, MX only

Hi Gang,

I just purchased a near mint 2004 yz450 and need to know what types of mods are necessary to make this baby work. It has an 8 oz fly wheel weight and a 50T rear sprocket(and a new chain). Any mods that need to be done? Or should I just ride it as is? I am intermediate, 185 lbs, in the Seattle area. I ride MX only. :cry:

Thanks in advance!


Ride as is, then invest in what you think needs improvement. Remember, cams provide more hp increase for less money then a pipe, and suspension is cheaper then a pipe but improves your confidence so you can actually use all the power of the bike.

Other then that, the chain should be replaced immediately becuase its such a pos. Replace it with a good o ring and your sprockets will last awhile.


Stock handlebar is crap and bends after slightest tip. You may like a higher bar and taller seat if you are over 6 feet tall. To keep your elbows up and wrists straight you may want a relatively straight bar too, but it is very personal and those you find out after you ride a bit.

If you ride MX only, you also may find that stock rear sprocket (EUR 47, USA 48) may suit better especially with the added flywheel weight you have.

Apart from these, you need no other mods if the bike starts well and runs clean. Dialling up the suspension makes a huge difference, but I do not think you long for more power for a while, unless you are not the average-Joe rider.

Keep the idle a bit higher and buy an Iridium sparkplug CR8EIX, and the bike starts even better. :cry:

cool, thanks guys.


ex-ama pro racer

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