The K&N SU-8001 is a washable, cotton-gauze panel element sized for the air box of the Suzuki VL800 Intruder and C50 Boulevard. Pleated media provides a large filtration area offering long service intervals, and the filter ships pre-oiled. Fitting it in place of the factory paper element means you clean and re-oil this one instead of buying a disposable filter at every service. The manufacturer frames it as a horsepower and torque upgrade, but owners on user forums disagree on how much a fuel-injected C50 benefits, so treat any gain as variable.
Fitment is the first thing to confirm before you order. The manufacturer's listing covers SUZUKI VL800 INTRUDER 2001-2008/C50 BOULEVARD 2005-2008, and owners on user forums report that KN does not make a filter for 2009 Boulevards. Removal is straightforward with a hex key, though the rubber seal can bind the cover, so budget a few extra minutes for a Suzuki Volusia or C50 air box service. Search terms this part answers include K&N SU-8001 C50 air filter, VL800 Intruder high-flow cotton filter, and Boulevard C50 air box cleaning.
The manufacturer's listing covers 2001-2008 VL800 Intruder and 2005-2008 C50 Boulevard models only. Owners on user forums report that K&N does not make a filter for the 2009 model, which uses a different teardrop-style air box. Confirm your model year against the manufacturer's fitment lookup before ordering.
Details vary. Owners on user forums report that a 2007 fuel-injected C50 adapted to the K&N filter without extra parts, because the bike's air pressure sensors let the fuel system adjust. Other owners on user forums warn that more airflow with an aftermarket exhaust can run lean and call for a fuel controller. Confirm with the manufacturer before assuming either outcome.
The manufacturer describes the filter as washable and reusable, and it ships pre-oiled. The listed re-oiling amount is 0.47 oz (14 ml). Owners on user forums say the element can be cleaned several times, but it eventually needs replacement once the media is worn or heavily soiled.
Owners on user forums describe the filter as a DIY job for a home mechanic with basic hand tools. On the C50, the front cover of the air box is held by two chrome Allen-head bolts. Expect the cover to stick, since the filter's rubber edges are compressed against the housing; owners report that wiggling and pulling frees it. When reinstalling, the cover may need to be reshaped slightly so it seats flush. Check the owner's manual for the correct torque and sequence, and confirm your model's steps before you start.
