Hi, I rode the DL from Europe to Australia, and sometimes in countries like Iran, Pakistan and Indonesia, had to use any "petrol" I could find (in Iran I had no idea, what the fuel was, because they have different alphabets). Only have needed to use bottled fuel a couple of times, though.

The thing seemed to work fine all the way. The only noticeable drawbacks, when using lower quality fuels were that you could hear engine knocking, if you used too much throttle at too low rpm´s. And sometimes fuel consumption went up by quite a bit, even up to 2 litres per 100kms - strange that this has actually been most evident in Australia, where there seems to be a really huge difference, whether you use normal or premium unleaded. I would´ve thought I´d get much worse fuel in the countries mentioned before!

I wouldnt touch the fuel system of the bike, because it works ok even in 3rd world conditions; you might actually do more harm by putting on additional filters, that could affect fuel flow.

One thing i definitely AM taking with me next time I´ll set off, is a portable filter, just a simple "sock", that can be put between the tank fill hole and fuel pump nozzle or fuel canister (or whatever it is your filling up from.) A real easy way to prevent at least the bigger dirt particles from entering. The more you will need to use bottled fuel, the more you will probably benefit from this extra filter.