Since OEM air filters for the Flavia 1800 are hard to come by and very expensive when you do find them, I am lookig at some alternative filters that could fit inside the Filter Box.
One that appears to meet the 55mm Inner Diameter (neck diameter) and 110mm Outer Diameter, is the following:
http://www.demon-tweeks.co.uk/performance/universal-air-filters/green-filters-universal-single-cone-cylindrical-air-filterMy only concern is that it may have too little surface area to meet the induction demands of an 1800cc engine.
Has anyone else got tried and tested air filter suggestions?