The K&N RU-1009 is a universal clamp-on air filter sized with a 6 in flange, 7-1/2 in base, 5-1/8 in top, and 4 in height. Instead of bolting to one engine, it grips a bare intake tube through a molded rubber flange. The manufacturer says these flanges absorb vibration and can stretch up to 1/16 inch to fit between standard sizes. The manufacturer also describes its universal line as pre-oiled and ready to use, so the filter goes straight onto the tube.
Buyers choose a clamp-on element like this when a custom intake, fabricated tube, or non-stock engine setup has no OEM filter that fits. Because the filter is washable and reusable, you can clean and return it to service rather than replacing a disposable element each time. Owners on user forums report that some K&N clamp-on filters fit tightly on certain intakes, so checking the tube's outside diameter against the 6 in flange before ordering is the step that prevents a return. Search terms this filter matches include 6 inch flange universal clamp-on air filter, K&N RU-1009 tapered intake filter, washable clamp-on air filter for custom intake, and 7-1/2 inch base universal air filter.
No. The manufacturer positions its universal air filters for a wide range of applications rather than specific makes and models. Fit depends on whether the flange, base, and top diameters match your intake tube, so measure before ordering.
The manufacturer states the molded flanges can be stretched up to 1/16 inch (1.5mm) to fit in-between sizes. That is a small allowance and not a substitute for choosing the correct diameter.
The manufacturer describes its universal air filters as pre-oiled and ready to use, so no separate oiling step is required before the filter goes on.
This is a slip-on, clamp-style installation that the manufacturer markets as easy. Fully loosen the hose clamp on the intake so it is not connected, then slide the rubber flange onto the tube and tighten the clamp. Owners on user forums recommend loosening the clamp completely so it can hang in the airbox while you position the filter, and applying a light film of lubricant to the rubber flange to ease it over the tube. Avoid forcing or heating the flange. If a flange will not seat, check its diameter against the tube before continuing, and contact the manufacturer about a replacement if the rubber appears misshapen, since owners on user forums report K&N has replaced filters in that situation.
