How To Clean Yanmar Fuel Injectors

Looking after the engine by regular cleaning will help to maintain it, however keeping the fuel clean is essential, contaminated fuel can lead to clogged fuel injectors. Fuel injectors are delicate instruments consisting of a nozzle and a valve. The nozzle is designed to atomize fuel – spraying it in the form of a fine mist into the combustion chamber. Over time fuel vapours can accumulate causing a deposit to build up which can eventually clog the fuel injectors and affect the engine's performance. Even the smallest particles of dirt can cause serious problems, and if water reaches the fuel injectors, the engine will stop. Another possible issue with water is its potential to spawn micro-organisms, which can rapidly multiply to block the fuel system. Even at the best marinas, some water will inevitably get into the tank at the fuel dock or via condensation in your fuel tank. Most engines generally have 2 built in engine filters. The primary filter is generally the largest and a secondary which catches fine particles of dirt and water that escaped the primary filter, water still however, poses a possible risk to the fuel injectors.

The following are possible symptoms of dirty or faulty fuel injectors:

Yanmar engine fuel injectors

Black smoke
Loss of power
Engine going into limp mode
Unburned fuel in the exhaust
Poor fuel consumption
High engine temperature
Poor idle
Difficult to start up
Lower speeds
Watercraft not getting up on plane
Poor engine performance - engine not running smoothly

Cleaning your fuel injectors

Fuel injectors must be monitored and kept cleaned. If your engine shows any of the above signs, then it is probably a good idea to clean the fuel injectors. This can either be done by a professional or you can do it yourself with an injector cleaning solution.

Fuel injector cleaning solution is specially formulated to remove deposits and contamination from the injectors, it can be purchased online or at a marine supplier shop.

The first step is to locate the fuel cap on your Yamaha outboard motor, and remove it. Making sure the tank is full, pour a bottle of injector cleaner into the tank. Replace the fuel cap, by turning it clockwise until it is tight, then start the motor and allow the cleaner to cycle through to the fuel injectors.

Alternatively you can hire a professional, some services will come and remove the injectors for you, whereas with others you will have to do it yourself. The advantages of hiring a professional fuel injector cleaning service are that they will perform a thorough check-up of your fuel injectors by disassembling them, examining them closely, then not only cleaning all the individual pieces, but also checking for any wear and tear. It is worth remembering that sometimes fuel injectors are not dirty, just worn and no amount of cleaning will improve a worn out injector, it will need replacing. If necessary, the professional service will also replace various seals, springs and washers as well as the nozzles, depending on the status of the spray pattern and atomization of fuel. Injectors atomize fuel at a specific pressure, they should also test and adjust them to this pressure. Any specks of corrosion or paint should also be removed, and they will be returned looking brand new.

Whichever option you choose, we recommend regular maintenance of your fuel injectors to avoid any subsequent engine problems.