Engine › BIG TWIN CARBURATED EVO W/FRONT MOUNT SPIN ON FILTER BIG TWIN CARBURATED EVO W/FRONT MOUNT SPIN ON FILTER $0.00 Easy access to oil supply for the installation of an oil coolerAutomatic thermostatic oil by-pass valveFlows oil through the filter first, for better flowBig-Twin carbureted EVO’s with front-mount spin-on oil filtersXL Sportsters, BuellsThe #4550 is required for oil cooler installation on `04-Up Sportsters Quantity: Purchase Added! Easy access to oil supply for the installation of an oil coolerAutomatic thermostatic oil by-pass valveFlows oil through the filter first, for better flowBig-Twin carbureted EVO’s with front-mount spin-on oil filtersXL Sportsters, BuellsThe #4550 is required for oil cooler installation on `04-Up Sportsters