i have an 04 rancher 350 es... just bout a dyno jet kit stage one along with a uni air filter. i do not have any other mods to my quad. will this add any performance? or anything noticable?
also with the air filter, do i just slide it over the ... i think its an anti backfire casing but im not sure... its what the stock air filter goes over... do i just put the new filter over this or completely take it out and just put the new filter in? thanks

 

Use the inner casing for the stock filter

 

no but once i put the uni air filter on... do i just slide that over the inner casing and take off the stock?