Petrol/2stroke oil ratio ?

They will run perfectly well on neat unleaded- until it seizes up Mack! The point is- the engine doesn't care what mixture ratio is used- it's the recommended dilution ratio of the oil by the oil manufacturer that is critical.

pleasant
August 2008

McCulloch MT 270,280,320 & MD 320,330 run on 20:1

MacK
July 2008

A popular misconception is to think the engine knows what ratio it needs, when infact the mixture ration is dictated by the manufacturer of the oil. Certain machinery manufcturers will give you a recommended oil/fuel ratio- either in the handbook or on the fuel filler cap. This ration is the recommended ratio for the manufacturers own branded oil and chances are you won't be using that. Simply purchase a good quality 2-stroke oil (I recommend at least a semi-synthetic) and refer to the dilution ratio printed on the bottle. Normally cheap mineral 2-stroke is diluted at 25:1, whereas better quality semi-synthetic is normally 50:1. Remember- it's the manufacturer of the oil that tells you what ratio their oil should be diluted to and not the people that make the machine.

Pleasant
July 2008