It does make a difference, make sure your running the right stuff! It is essential to use the correct oil for your outboard, especially if you have a fuel injected outboard.


Each engine manufacturer spends millions of dollars developing oils for their engines. With fuel injected engines, such as the Evinrude Ficht or D.I and E-tec, the oils are specially formulated to stop carbon building up on the fuel injectors. These oils are more expensive, but the extra cost is well worth it.


If you have a fuel injected motor, be it a Mercury Optimax, Yamaha HPDI or Evinrude E-TEC etc I suggest purchasing the oil designed for the specific engine. Carburettor engines aren't so critical when it comes to oils, however you need to use marine outboard TCW3 oil.


Personally I always run an outboard manufacturer's oil. I have found that these oils are superior in lubrication and corrosion resistance over many of the other oils available.


When filling up your oil bottle, be sure to use the same oil every time! Mixing oils may cause the different brands to react, causing a sludge build up at the bottom of the oil bottle. This will eventually block the oil pickup or pump resulting in Powerhead damage.


If you have just purchased the boat and don't know what oil is in it, it pays to run the oil bottle down low, then start running the oil of your choice from then on. As always please consult your local specialist prior to undertaking any changes. On a pre-mix engine it doesn't really matter about mixing oils. As long as you run the outboard on TCW3 oil.


The mix that I run and recommend to all my customers is 50:1. This goes for any two stroke premix outboard. If you run an old outboard like Seagull for instance you will need to get in touch with your dealer as they run a much richer oil mix.


You may notice that on some smaller motors there is a sticker recommending you to run 100:1. From experience 50:1, in my opinion, is much better for the motor and with the extra oil in the mix it tends provide superior lubrication and helps to prevent corrosion of the internal parts of the motor when it is not in use.


In my F3 race boat I run a mix of 20:1, I put 1 litre of oil into 20 litres of Av Gas and I have never had a problem with fouling spark plugs. I always run the highest octane fuel the petrol station has available. It doesn't cost much more and the engine will love you for it, especially if you don't use the boat often.


Outboards have a minimum octane requirement for the fuel you use. Petrol available in New Zealand isn't that great, if you imagine your engine requires a minimum of 91 octane. If you use 91 you would probably be lucky for it even to have a true 91 rating. After you leave it sitting for a few weeks or months it will have deteriorated to well below the minimum requirement.


So always go higher!


If you are using the boat frequently and you run a Japanese 4 stroke outboard like Yamaha or Suzuki, 91 octane will be fine. But in my opinion all carburettor 2 strokes and especially American motors require 96 or above. Always check your handbook or contact your local dealer.


When storing the boat it is best to have the fuel tanks filled right to the top. When the tanks are low there is a lot of air in the tanks. This creates a risk of condensation, so top them right up.


If the boat is going to be stored any longer than about 2 months, I recommend putting some fuel conditioner into the fuel to help maintain the octane level. This is available at most of your local outboard dealers. Simply fill the tanks and mix the conditioner in. Your fuel will last months longer!
If you want to buy then you should but never be that lazy so that you did not check out the compatibility of your oil or lubricant with your motor.