The secret to a happy engine? Good fuel

When it comes to engine troubles, fuel contamination is the biggest culprit. Over Easter, we wrote about staying safe on the water, and making sure your fuel was fresh over the Long Weekend to avoid issues with engine failure.

Today, we’re digging deeper by sharing tips and best practices for your marine fuel.

  1. Stay fresh

Yep, we said it once and we’ll say it again, the best fuel is fresh fuel, so make sure you’re not operating your vessel with any fuel older than three-months in the tank. This is also why many engine manufacturers recommend filling up at busy petrol stations, since their fuel will have a higher turnover rate.

30 days is the max recommended* storage time for ethanol-blended E-10 (if weather is hot or humid, this is less). If you can, use unleaded, higher octane fuel (premium fuel) in your outboard to protect it. If E-10 fuel is the only choice, run it down before storing your vessel.

* According The Outboard Engine Distributor’s Association.

  1. Avoid E-10 fuel

Since premium fuel is available at all petrol stations these days, it’s best for your engine to avoid E-10 altogether. Yes, many marine engine makers will tell you ethanol fuel under 10% content is safe in Australia, but in reality, it’s far wiser and safer to avoid E-10. (See point 3 for more on why.)

If you’re operating a larger outboard, premium unleaded is the best choice possible. Yes, it’s pricier, but your engine will perform better for longer, and your boat will go a greater distance too. If performance is not a big deal to you, and your outboard is smaller, then regular unleaded will do the trick.

  1. Top her up

It’s never a good idea to run your tank down to empty and allow the stuff at the bottom to be drawn up (including sludge). Most experts recommend keeping the tank three quarters full, to stop condensation from building up on the inner-walls. If a tank is partially full, it can draw air in, which expands and contracts, causing moisture to condense in the tank.

Ethanol blended and biodiesel fuels are hygroscopic, which means they absorb moisture and are not ideal for marine tanks. This is why it’s better not to use them at all. If you have to, don’t leave the fuel in the tank for any length of time, as it will soak up water and mess with your engine.

  1. Filter

Although a filter should be fitted to every outboard, experts suggest that in this, ‘age of uncertain fuel mixes,’ we should be fitting bigger, primary filters – ideally an in-line 5-micron separating filter plus a 20-micron spin-on filter. If you have to choose just one, opt for a 10-micron filter. Whatever you end up with, be sure to clean or change it within at least 50-hours.

Removing the filter with a strap wrench allows you to check on whether there is contamination in the fuel tanks, and if so, they can be drained. Regardless, draining primary filters every three months or so is a good idea. Clear site canisters also allow you to see whether debris or water is collecting inside, which makes it easier to assess condition.

  1. Check it

Keep an eye on your fuel lines, fuel tank caps, deck fillers and breathers. Fuel lines, plastic connections and hand-primers have a fixed life-span, and leakages are often caused from a split hose close to a constricted hose clip. Screw caps that leak are another thing to watch out for, so check the rubber ring around the cap for deterioration, as over time, this can happen.

Leaky caps, as well as deck fillers on larger boats can cause water to come inside, so be sure to check these are in order. Breathers should be on portable tote tanks and shut in transit when open to the weather. Crack the breather a bit to allow it to expand (if protected) and be sure to open it up when you’re using the outboard (of course!).

Are you covered?

Talk to us about ensuring your boat is comprehensively insured for the stuff that matters. We offer obligation free quotes and can review your existing marine insurance to ensure it’s doing the job right. Get started now, and for more tips on marine fuel, head to this resource.