On Bonneville's with carburettors there is a small fuel filter fitted inside the fuel pipe where it fits between the 2 carbs, Just something to check if you breakdown due to fuel starvation. I have just removed mine and will fit a external plastic filter from a car accessory shop. Not a job you would want to do on the side of the road if you broke down, I had to remove seat, tank and sidepanels. this should be a service item, you would think they would make it easier to remove and clean,