What to do when you can't start a portable diesel generator.

Diesel engines are very simple machines. When they fail it is often a fuel problem. Less common is some mechanical engine failure that has resulted in a loss of compression. Loss of compression can be caused by a cracked engine, broken valve, warn piston rings or more commonly just some valves out of adjustment and that is easily fixed. First here is what you should check if you are using a single cylinder Yanmar type diesel engine.

• Use diesel motor oil only. 15w40. Do not use motor oil for gasoline vehicles. You will cause engine damage.
• Use regular automotive diesel fuel. Other fuel type have a different flash point and may cause you problems.
• Keep in mind that very cold fuel will gel and clog up fuel lines and filters.
• Make sure you are under 3000 feet elevation. Air density is about 10% less at 3000 feet and it will be hard to start your diesel.
• Battery must be charged. Slow cranking results in to little heat and compression to ignite air fuel mixture.
• Throttle should be in the run position. Inside the engine it is connected to the fuel pump and closes a valve causing no fuel to enter the pump

Read more: Trouble Starting Portable Generators

Oil Changes & Valve Adjustments

Service for the generator set is much like the service you perform on your automobile. The generator set should have oil and all filters changed on a regular basis The generator should be kept free from dust and occasionally connections should be checked for looseness. These procedures are normally done every 100 hours or 3 months whatever comes first as suggested by our maintenance schedules. Severe weather patterns can increase the maintenance requirements, i.e., excessive dust, heat, moisture. Also any commercial type use or prolonged usage. The unit should also be checked from an electrical standpoint to be sure that it is performing as it was designed.

Oil Changes

Engine oil has limited life - after a certain point it starts losing lubricating qualities and carbonizes. Once it happens, the engine gets contaminated with carbon deposits or sludge that significantly shorten engine's life. When you change oil at or before manufacturer suggested interval, you change the oil before this "carbonizing" point, engine remains clean and once refilled with new oil ready to work hard again. If the engine oil has not been changed for long, carbon deposits start clogging the oil pickup screen decreasing oil supply and increasing friction. Compression decreases and engine start wearing much faster.

Read more: Oil Changes & Valve Adjustments

Generator Valve Adjustments

How to do a Valve Adjustment on a portable diesel generator It only takes 5 minutes to adjust the valve clearance on your generator. This video shows you how easy it is and is part of a series of videos Aurora Generators uses to show owners of its generators how to take care of them and avoid repair costs. For reference the intake valve is adjusted to 0.15 mm and the exhaust is 0.20 mm

Read more: Valve Adjustment Video - Portable Generators

Changing Oil Filter - Video

Changing the oil filter is really easy on a portable diesel engine like the Yanmar 186 diesel motors BUT, there are something you need to know. Watch for the little o-ring on the oil filter and make sure it is not pinched or damaged in anyway. If your oil filter does fit all the way into the engine you will have problems. Here's why.  Many people who find it is not inserted in all the way report that the engine runs for a few minutes then develops low oil pressure and safely turns itself off.  If the seal is bad then it sucks in air, may drip when not in use or cause a oil passageway inside the engine to be blocked resulting in low oil pressure.

Read more: Changing The Oil Filter - Video

Bleeding Air from your fuel lines.

Yanmar diesel generator engines use a high-pressure, direct injection fuel delivery system. Fuel is drawn into the system with the lift pump. The high-pressure fuel injector pump then pressurizes the fuel and delivers it, in precisely metered bursts, to the injectors through the fuel oil piping. Any air in the fuel system can lead to an erratic or non-running condition. Air should be bled from the fuel system whenever the fuel oil filter is changed or any of the fuel oil pipe fittings are loosened. The fuel oil filter must be primed with diesel fuel during the filter change in order for the lift pump to be able to force fuel through the system and bleed the air out.

Read more: Bleeding Air Our Of Fuel Lines

Generator Break In Period

All engines require some kind of break-in period. Current technology provides the means of manufacturing engine parts with unimaginable precision but they still fall short of achieving the near perfect fit that a proper break-in will provide. “Break-in,” for the most part, is the allowance of the machined cylinder and ring surfaces to conform to each other’s shape during engine operation. This conforming or “mating” of ring and cylinder surfaces is the ultimate goal of a proper break-in. “Mating” these two specific parts will produce a very tight seal in each cylinder. A tight seal is very important because it prevents the escape of unburned fuel and pressurized gasses into the crankcase, while further preventing crankcase oil from entering the cylinder above the top compression ring.

Read more: Generator Break In Period

Generator Fuel Pump Service Video

There is seldom a need to remove or service a fuel pump on your diesel generator however if your troubleshooting, can't start your generator or want to make fuel injection timing adjustments then this video is for you.

The lift pump - fuel pump is a spring loaded plunger and barrel mechanism. It rests on the camshaft and at right moment the camshaft lobe pushes the pump, pumping fuel up to your fuel injector. This timing is critical. The only way to adjust this timing is to physically move the pump closer or farther away from the engine camshaft so you effect when the lobe contacts the pump.

Read more: Generator Fuel Pump Service VIdeo

Torque and Timing Adjustments For Portable Aurora Diesel Engines.

* Required torque and timing adjustments necessary for the proper operation of your engine.

Valve Timing

Model / Item	Phase (Degrees)
Intake Valve Open	BTDC18°	BTDC13°
Intake Valve Close	ABDC46°	ABDC52°
Exhaust Valve Open	BBDC52°	BBDC57°
Exhaust Valve Close	ATDC12°	ATDC8°30'

Initial angle of fuel delivery

Read more: Portable Diesel Generators Torque and Timing

Diesel Fuel Injector Service Video

Diesel engines use direct fuel injection -- the diesel fuel is injected directly into the cylinder.

The injector on a diesel engine is its most complex component and has been the subject of a great deal of experimentation -- in any particular engine, it may be located in a variety of places. The injector has to be able to withstand the temperature and pressure inside the cylinder and still deliver the fuel in a fine mist. Getting the mist circulated in the cylinder so that it is evenly distributed is also a problem, so some diesel engines employ special induction valves, pre-combustion chambers or other devices to swirl the air in the combustion chamber or otherwise improve the ignition and combustion process.

Read more: Fuel Injector Service Video

Many parts moving inside the engine create vibrations. Internally a balancing shaft offsets most imbalances. Any remaining oscillating forces that would normally be transmitted to the foundation are dampened using Anti Vibration Engine Mounts. For the engine mounts to do their job they must have a solid foundation to work against. Without this, the engine cannot work properly and will damage itself from the vibrations. Portable generators installed on a vehicle or boat will often break down faster. Portable generators need to be used on the ground or mounted on a firm surface. Personal residential use is what most warranties cover and that means it most often sitting in your garage for example and used from time to time, NOT eight hours a day to power your truck A/C or your boat for example. Note that shaking when the engine turns off is normal. There is a huge amount of torque in portable generators and during shut down they will shake. This is normal.

Generator Batteries that will not charge

Did you know you have two alternators on your generator? Behind the flywheel of your engine is a smaller alternator. It is called the "Flywheel Generator" The Flywheel Generators are used to produce power necessary to charge the starter battery. This little generator should not be confused with the much larger alternator that the engine is connected too. The flywheel generator produces AC voltage that must be converted to DC in order to be used as a battery charger. A very simple 12 volt regulator is used. It has cooling fins on it and is mounted to the engine block.

Read more: Battery will not charge

Generator Break In Period

All engines require some kind of break-in period. Current technology provides the means of manufacturing engine parts with unimaginable precision but they still fall short of achieving the near perfect fit that a proper break-in will provide. “Break-in,” for the most part, is the allowance of the machined cylinder and ring surfaces to conform to each other’s shape during engine operation. This conforming or “mating” of ring and cylinder surfaces is the ultimate goal of a proper break-in. “Mating” these two specific parts will produce a very tight seal in each cylinder. A tight seal is very important because it prevents the escape of unburned fuel and pressurized gasses into the crankcase, while further preventing crankcase oil from entering the cylinder above the top compression ring.

Read more: Generator Break In Period

Portable Generator Erratic Engine Speed

Engine speed is directly proportional to the amount of fuel the fuel pump sends to the fuel injector. The amount of fuel the pump can pump is controlled by a metering valve. This metering valve is part of the fuel pump assembly. The throttle moves this metering valve between closed and fully open or any position in between to control engine speed.

When there is a demand for more power such as under heavy load more fuel is needed. The pump gets more fuel because the speed governor makes minor adjustments the metering valve. The governor is a centrifugal wheel that pushes against the throttle to make speed adjustments. The pushing and pulling is all done with two springs rather than physical contact so if the tension is not correct it can't do its job. To check the cause of erratic speed simply hold the levers that the springs are connected too and increase the speed manually. Hold it and see if the engine speed become stable. If it is, then you need to make adjustments to the springs. If the engine will not stabilize, then it is NOT related to the governor operation. You have some other fuel or fuel delivery issue.

Read more: Erratic Engine Speed

Generator Batteries

Portable Generators.

Before you use your generator make sure your battery is charged. If it is not fully charged you may be able to still start your engine however the flywheel generator that is used to recharge your battery may be overloaded. Overloading the charging circuit maybe blow a fuse or causes further damage that is not covered by warranty.

Standby Generators

Standby Generators use two methods to charge and maintain their batteries. One is an alternator just like on your car. It will recharge the generator battery when it is running. The second is a power supply / battery charger that is built into Aurora Generators that gets power from your mains when available and helps keep the battery topped up.

Read more: Generator Batteries