These operate by throwing any deposits in the oil to the outside as they rotate. To clean them, they are separated and the deposits are scraped out. After washing in paraffin, the two halves are reassembled.

Some centrifugal filters carry ignition timing marks; these should be marked with a dab of paint so that they can be ref fed in exactly the same position in relation to the engine-driven half, otherwise the ignition timing settings will be lost.

Step 1. Place a drip tray under the filter unit.

2. Mark the cover for reassembly in the same position. Loosen the bolts.

3. Remove the bolts and cover. Clean the interior with a brush and paraffin. Reassemble.