Outboard Technical talk

Is your Petrol Fresh?

Has your petrol been sitting in the boat all winter? If it has, it is more than likely stale.
Stale petrol can cause your engine to be hard starting, idle poorly, run erratically and in severe cases it can cause engine damage!

Petrol does have a shelf life
Outboard and sterndrive engines are manufactured and tuned to run on a minimum octane rating. The issues we face as boat owners is when the boat is stored all winter, the fuel in the boat goes through extreme weather conditions. It sits in the sun all day, then cools down to freezing temperatures at night time. This constant heating and cooling of the fuel everyday causes it to go stale very quickly. If your motor is recommended to run on 91 octane fuel and you use 91, it won't take very long for the fuel quality to drop below the recommended octane.

Octane is the fuels resistance to detonation/pre-ignition. If your two stroke isn't running as well as it should, you might be over propped and causing the engine to be excessively loaded, with a fuel that is not up to standard you can cause the engine to overheat in the combustion chamber and detonate. This detonation can very quickly melt pistons and do severe engine damage before you even realise anything is wrong.

The best precaution for minimising the risk of stale fuel if you have an under floor tank is to fill the fuel tank up with a high octane fuel and add a Fuel Stabiliser Treatment. These products are designed to keep fuel fresh and to prevent the additives in the fuel from breaking down, dramatically extending the life of your fuel.

If you have half a tank of fuel that has been sitting only a month or so. Fill the tank up with a high octane fuel like 98 to help give your fuel a 'kick'. If it has been stored with a half empty tank, you should drain your water seperating fuel filter to make sure that condensation hasn't built up over the winter months. 

Are you using the correct oil for your outboard? Click here