Oh crap. I just had one that belonged to a large railway construction company. Driver put 130 liters of gas in and drove it untill 1/2 tank. We figure about 300km or so. I quoted the job and talked it over with thier fleet maintenance manager, He was happy with the info I gave,and ready to do it. He went to his bosses and they said no, drain it, flush it and fill it back up with new fuel and put a few botttles of 2 stroke oil in the tank. Against my will I did it for them, and to my surprise the truck runs Good, time will tell for how long. I did make them aware that by not properly repairing it they will likely have an engine failure and it will not be covered by warranty, but they thought it was worth the risk.