Just a sudden thought - with all this talk of different fuels?.
Anyone remember TVO (Tractor Vapourising Oil), which was a cheap and nasty paraffin product. Old tractors had two tanks, one petrol and one TVO, you started the engine on petrol, but once it was warm switched over to TVO, which was a LOT cheaper (like red diesel).
As kids we used to have an old pickup truck (Ford Popular) we used to run round the fields - we disconnected the fuel tank and replaced it with two mootorcycle tanks in the back - one with petrol, one with TVO - used to work fine, and we could 'steal' TVO from a big tank on the farm (we had to buy the petrol).
Note though, it's a VERY low octane fuel - not suitable for modern engines.
We used to mix it in the petrol on old motorbikes as well (Norton, BSA, Matchless etc.) which stretched the small amount of petrol we could afford.