Tractor Vaporising Oil (TVO) can be mixed using petrol and heating oil.  FOFH give some good guidance on mixing TVO.

This is the method and ingredients they recommend….

There must only ever be 2 ingredients in TVO1. Petrol (unleaded is absolutely fine for a Ferguson tractor) 98 Octane.
2. 28 Second Heating Oil 20 Octane.

Aim for an Octane value between 55 and 70.

55 if doing very hard work
70 if doing topping and the like

To give you some idea of the sums:-

1 part petrol and 1 part heating oil comes out at 59 Octane.
2 parts petrol and 1 part heating oil comes out at 72 Octane.
1 part petrol and 2 parts heating oil comes out at 46 Octane.
Petrol on its own is suitable for road runs (with the heat shield removed).

Octane is not the only factor, but it provides a good guide.

Diesel fuel is designed to cause ignition by compression and will encourage pinking. It is not designed to burn in TVO tractors, and no upper cylinder lubricant is required in these tractors, so do not use anything other than petrol and heating oil.

Using fuel which does not burn completely will destroy the lubricating properties of the oil and that (in a Ferguson TE tractor) will result in wear to the cam shaft bushes and then loss of oil pressure from cam shaft bushes. Loss of oil pressure will, then result in damage to the crank shaft. Lubricating oil in a TVO tractor’s engine should be changed according to the Tractor Instruction book.

Related information….

Ferguson FE35 thermostat, jet information and identifying if your tractor is a VO or Lamp Oil version.

How to get a good mix of TVO.

Bob Callaby says:

March 27th, 2008 at 3:52 pm
With regard to your TVO mixture this seems to differ widely from that employed by friends of mine. The most common mix seems to be 20 litres of kerosene, five litres of petrol and 1/2 litre of two stroke oil. Some use diesel instead of two stroke oil but this seems a pointless excercise while a few even use straight kerosene on Case tractors with very good vaporisers, temperature guages and efficient rad blinds. Regards Bob

Mick Boakes says:

April 22nd, 2008 at 7:09 pm
I wonder if you can help? I have just refurbished a Fergi t.e.a.20. It ran well before and after but alas on the christmas road run no 3 cylinder went dead.I have replaced plugs,points condesor,coil, there is no water in oil no oil in water, but have noticed that after cleaning plug, will often fire for a short time if plug cap is left loose,Have now run out of idea,s have you any?
Many thanks Mick

ian says:

August 22nd, 2008 at 2:10 pm
hi mick you will probaly havto take the head of .i think you could have a valve stuck or at worst a burnt out one mail me bake if i can be of more help