Air Filter Honda XR/CRF 50 '00-'18 / XR/CRF 70 '97-'18

A dual-layer open-cell foam air filter from Putoline, made to fit the Honda XR/CRF 50 and XR/CRF 70. It drops straight into the standard airbox and is designed to be cleaned, re-oiled and reused rather than thrown away.

Open-cell foam works differently to paper or cotton gauze: the honeycomb of uniform, interlocking cells traps dirt throughout the full depth of the element instead of only on its surface, so the filter holds a large volume of dust while still flowing air freely. Putoline pairs a coarse outer layer with a finer inner layer to catch the small particles that do the real damage to pistons and rings.

A sensible choice for parents and riders maintaining junior trail and pit bikes, particularly where the bikes see dusty tracks and frequent filter servicing. Filter oil and cleaner are sold separately.

• Direct-fit replacement air filter for Honda XR/CRF 50 and XR/CRF 70
• Fully reticulated (open-cell) foam construction for high airflow with high dust-holding capacity
• Two-stage design: coarse outer foam for dirt, grime and sand; fine inner foam for the smallest particles
• Outer and inner elements are fused together so dirt cannot lodge between the layers
• Purpose-formulated adhesive on the glue seams to resist breakdown from filter oil and cleaner
• Thick, flat, greaseless foam sealing ring seals against the airbox and acts as a breathable gasket
• Washable and re-oilable for repeated reuse
• Putoline SKU PUTAFHO429

Oil the filter before first use — foam elements do not filter effectively dry. Work a dedicated foam filter oil evenly through the foam until the whole element is uniformly coloured, then squeeze out the excess.
Do not apply oil to the flat foam sealing ring; it is designed to seal greaseless against the airbox.
Clean with a purpose-made foam filter cleaner or warm soapy water. Squeeze the foam gently — never wring, twist or stretch it, as this tears the cell structure and can split the glue seams.
Avoid petrol, kerosene and harsh solvents; they attack the foam and the seam adhesive.
Rinse thoroughly, squeeze out the water in a clean towel and allow the filter to air dry completely before re-oiling. Do not use direct heat or a naked flame to speed drying.
Inspect the foam and glue seams each service. Replace the element if you find tears, thin patches, hardening, or seams that have started to separate.
Service more often in dusty, sandy or muddy conditions, and check the filter after every ride in those conditions rather than waiting for a set interval.
When fitting, seat the sealing ring squarely against the airbox face so there is no gap for unfiltered air to bypass the element, and make sure the airbox and intake tract are clean before installation.
Keep a second oiled filter on hand so the bike is not down while one dries, and store spare oiled filters sealed in a plastic bag in a cool, dry place out of direct sunlight.