what is it, and what does it actually do?
on two strokes they are noted for shooting flames out tailpipe. basically just used to prevent fires
so if i remove it from my stock exhast setup, which is really really eaasy to do…then i shouldnt have any problems? its a 4 stroke 350 raptor
it seems like it is so restricting that theres no good reason not to remove it, and i should have an aftermarket exhuast setup by summer anyhow.
wikipedia…
A spark arrestor is a device intended to prevent combustible materials, usually sparks or other tiny flaming debris, from escaping into areas where they might start fires.
They are most commonly used in conjunction with motor vehicles (inserted into the muffler), as well as improving safety within fireplaces, and various electrical equipment. Often, a spark arrestor mimics a net fashioned from tightly interwoven wire gauze built to resist bits of ash, sparks or other such dangers
that would be pretty shitty to start a forest fire from riding a quad 
does your quad have it stock? i know stock exhausts have those core baffles but that isnt really the actual spark arrester always. yes, you can probly remove the baffle easily and get alittle more power but i’d have to see the setup.