First things to check when the boat stops dead BRISBANE
Wayne Kampe wkff@aapt.net.au
I’m no marine mechanic, but I’m a boat owner who has seen some of the things that can spoil a day on the water. It’s something nearly every boat owner experiences sometime. The boat is humming along quite well and then suddenly, there’s no sound from the engine, or it revs really high and the craft isn’t moving. It’s running rough and can’t seem to
breakdowns but can help with tows off sand banks and many other marine issues. FUEL SUPPLY With smaller engines hooked up to a tote tank of fuel, we could rightly regard fuel supply problems as a prime suspect for many stoppages. I once saw the in-tank pick up pipe that sucks fuel from the tank and up to the main fuel line connections fall off the metal fitting into the bottom of the tank, on a brand new fuel tank. This meant that the engine would start when fuel was slopping around in the
the boat and fill it at the local service station, after which the cap is given some serious tightening to prevent nasty petrol smells escaping in the car. I’ve done this myself. Another fuel issue comes from the click-on connection between the fuel line and tank coming undone, which they sometimes do. This can be rectified. A couple pumps on the fuel primer bulb will often get things moving again. All fuel line connections that are accessible are also worth scrutinising. Cheap factory clips can come loose,
The isolator switch is one item that can get up to mischief. Replacing it every couple of years is a smart move.
Clips on fuel hoses can work loose and are a common cause of engine stoppage. snap out of it. None of these scenarios are what boaters want, but things happen. A few thoughts on the topic won’t go astray. Most small craft are outboard powered, so we’ll stick primarily with these engines. Remember, this is
near full tank and run for a few seconds before stopping again. It was frustrating and took time to find – an extremely rare occurrence. If the boat suddenly stops after running a bit ragged for a few seconds, and then refuses to start, fuel issues
connections come asunder, the primer bulb can split (a band-aid will fix it) and all these situations can let air into the fuel line to interfere with engine suction. If a dodgy clip is diagnosed, sometimes merely cutting off a small bit of fuel line
injected engine should be given time to idle for a while until it’s running smoothly. Full fuel flow needs to be resumed or the engine will struggle to run evenly under load, simply because the engine computer needs to be satisfied that all’s well, including fuel flow. An older style two-stroke won’t suffer from this short delay – with fuel in the cylinders it’s ready and willing to go. ELECTRICAL ISSUES Outboard engines come with emergency cut out switches – the kill switch. It’s important to ensure that the switch is engaged correctly on the tiller arm, or up near the forward controls where these are installed, otherwise the engine will never start whether it’s a key start or pull start model. If a pull start engine won’t fire up after apparently running well, and fuel tank cap or lines are eliminated as the problem, I’d be casting hard looks at that kill switch. The trouble is, without some electrical knowledge, not much can be done on the water, apart
from disconnecting and reconnecting the switch into it’s clip, to try to overcome or bypass a possibly bad electrical contact. Incidentally, the latter tactic is worth trying. Electrical issues can occur in both small and large engines. One of the most common is a total battery failure. Any boat battery can fail after a few years of sitting in a boat, so it’s wise to have the battery load tested from time to time to assess its health. Even a good battery can drop it’s bundle. A canny boat owner will be grateful for the alternative pull start system the engine has, or will have read the service book that came with the engine and know exactly how to get a rope onto the engine’s fly wheel to give it a pull start. I saw a mate start a 90hp outboard with a rope while we were a long way off the Gold Coast. He knew which parts of the shroud around the flywheel to remove, had the tools aboard to do it and he did it at home as an exercise. He was confident in the whole procedure.
Another culprit for electrical failure is the good old battery isolator switch, if fitted. These items are not bulletproof and if one’s subjected to spray or is located in a place where it can be damp for a fair time, maybe in an enclosed hatch, it can easily short out and stop the engine. Worse, it can fry the engine computer. Maintain your VMR membership as the engine sure won’t be starting again that day. If the isolator switch has dropped its bundle, it’s likely that all electronics can drop out as well, because power won’t be exiting the battery. Have the phone aboard to ring VMR. In truth, electrical problems from isolator switches are a lot more common than is generally understood. Replace the unit every couple of years if it’s in a place where salt water or salt spray can get near it. PLENTY NOISE, NO PROGRESS Let’s take another scenario: the boat has been running well but there was a brush with a sand bank or
VMR membership is an important part of boat ownership. When all else fails, a tow home is far better than sitting in the sun with the fun quickly departing from the day. about trouble shooting first – if a total engine failure occurs, there’s not much to do except organize a tow home. Membership with the Volunteer Marine Rescue is a great safeguard, as this facility not only assists with 102
NOVEMBER 2016
should be a primary suspect. Take a look at the fuel tank and see if the breather on the cap has been opened or if the cap has been loosened a turn from when the tank was last filled. Boaters often remove their fuel tank from
and reconnecting a tighter section via the clip will keep things going well enough to get home. Be advised before powering off, once a fuel issue is solved and the engine fires up, a fuel
The good old kill switch – when exposed to salt water these systems can cause engine stoppage, but sometimes removing and then replacing the unit can see it working again.