They are also useful for your drinking water filter - keeps most of the crud away and reduced any need to clean the fine filter. Simply wrap around the inlet and tie off with a rubber band. For fuel you'll need some sort of contraption to keep the filter in place.

All the inlet filters suffer from the same kind of problem - flow restriction. This means that the normal flow out of the petrol pump can be way too fast for them and they overflow. If they do handle the full flow then either they are physically big or they don't filter out fine contaminates.

I think the 'Mr Funnel' filter is the only one that gets rid of water. Used by diesel and aircraft people as they really don't want water.

http://giantloop.smugmug.com/Motorcy...GOPR0651-L.jpg
You're exactly right. The filler neck filter made it extremely time consuming to fuel up during my Baja trip - especially at gas pumps that click off with back pressure. But it also gave me some peace of mind . . . Guess I'm still looking for the perfect solution.

Hi Olaf -I can only speak of my own moto ( F650 Dakar)-
I have a primary filter in my main tank- and I've added a washable filter before reaching the bike's OE filter and regulator. (see red and blue pic)

The fuel from the outer two fuel tanks goes through two disposable external filters before entering feeding the main tank.
It all works a treat and has never missed a beat- The investment in the washable filter made it all worthwhile as the bmw OE is some $150 a time to replace :0(

At worse, 3 filters and at best, 4! ( not counting Mr Funnel!!!) :rofl: :blushing:
Preventing contaminated fuel entering your tanks, if still the first and best solution and for that I chose Mr Funnel.

Maybe part of some solutions for you?