ok im showing my ignorance!! i have been chasing a problem with a 2001 600f4i i purchased and i just realized that there are not any velocity stacks in the airbox none what-so-ever, just open throttle bodies in the air box. so my question is: what would no stacks cause? and what exactly do they do?

 

It would make the bike run like crap with peaks and flatspots in the power range as well as the engine feeling rougher running.

 

thats exactly what i was hoping to hear!!! thats my problem.. i have a set of stock ones ordered and on the way.