well what we do in the serivcing bay in the army with the veichles that have the wrong fuel in them is drain it then get some brake fluid in a cap from a bottle put some bralke fluid in the cap and pour it in the inlet of the carb this will make it smoke white and smell but levave it running the somke will clear then all fine it cleans the carb and the inlet bits and bobs ,apperntly a very very old trick but it dose work i do it evry winter
containtion of fuel will not do any harm but make the engine run like a bag of nails and do you fuel filter in ,deislo in a petrol car = smoke it will run for a little bit but not long as its for conbustion engines as petrol is for ignition engines (spark induced) petrol in a deislo will do damge runn like a bag of nails ,damge to the fuel pump ,damged to the lift pump etc