the balancer shafts are designed to reduce "second order vibrations"

in layman's terms... they reduce engine vibration to increase comfort.

many older 4 bangers dont have counterbalancer shafts, and they dont shake themselves apart nor spin main bearings/rod bearings as someone else suggested.

as they are designed only to increase driver comfort, there is no other detriment to removing the belt other than decreasing driver comfort.

i havent run balancer shafts in my H22 for over 3 years. i dropped the H23 VTEC setup into my car about 6 months ago, and i left off the balancer belt in this case also.