just looking at replacing a external fuel filter I had fitted to my boat.I have about 60 hrs on motor which is a about 3years old ,so thought I might replace it . The filter is a cav type with clear bowl on the bottom,reading the whitworths site for replacing cartridges it says its not reccommended for petrol.I remember when I order my tinny I wanted an extra filter fitted to look after motor and I think the dealer said the cav diesel filter cartridges were alot cheaper than racor petrol type ones but did the same job. just after any advice/feedback differences between filters changing frequency etc cheers Yamp