i have owned my 400ex for like 3 months now and my valves are making quite a bit of noise now... i know they need adjusted and im working on that right now.. but what i want to know is running the bike without adjusting your valves does that hurt anything or does it just make the performance of your bike crappier till u adjust them
thanks

 

im not to sure if you leave it it will heart anything??? but i would adjust them it does make the power better than off set valves im adjusting mine as well i have a 01 300ex iv only riden it for about 4 mounths though good luck its not hard to fix.

 

I don't think it'd really hurt it. But just remember it's better to set your valves just a hair loose then tight. It helps with power.