I have no idea what this post is doing here, but to provide an answer, if there is no compartment separately for oil, then it is a 2 stroke engine, meaning that the oil for lubricating the engine has to be mixed with the petrol, usually at a ration of 50/1 petrol to oil, but check with the machine specs. This has to be done every time that petrol is added. Get a separate one gallon can only for this machine and mark or label it. Mix the full gallon at the proper ratio for that engine and remember to shake the can well before each refill of the machine as the oil and petrol separates to some extent when left to settle.