Ample Power Genie$^{tm}$
Installation and Wiring Instructions

Ample Power Models G12-150, G24-75, G12-280, G24-175 October 20, 2004
Copyright ©1989 through 2004. All Rights Reserved - Ample Technology


This manual covers the standard engine and system wiring for the diesel battery chargers manufactured under the Genie brand name by Ample Technology. These l units are operated by a manual control switch in conjunction with a Run Controller which shuts the engine off in the event of low oil pressure or hot water temperature.

The Genie is a powerful battery charging system which uses a Kubota engine to drive a custom high output alternator. The marine engine is freshwater cooled with a bronze and cupro-nickel raw water heat exchanger. The land based unit uses a radiator.

The alternator is controlled by a Smart Alternator Regulator, SARV3, including temperature compensation and current limiting. The alternator regulation circuits are integrated within the EnerMatic Controller.

Major Components

There are three major components to the standard Genie. They are: the engine assembly, the control panel, and the run controller assembly.

NOTE: The standard Genie can be converted to use the EnerMatic Controller by the addition of the flywheel gear tooth sensor.

History of the Ample Power Genie

The Ample Power Genie has been in production since 1989 with many thousands of Amp-hours produced for thousands of happy users. The unit has been improved in many significant and minor ways since it was first introduced and is truly unsurpassed in performance.

In 1988 the owner of a remote cabin asked us to design a diesel battery charger. He recognized that using a generator to make AC, when he didn't need AC, wasn't the proper way to use resources.

During the design and construction of the first Genie, we couldn't help but tell some of our sailing friends. After seeing it in operation, they wanted one too. The Genie has proven to be reliable and highly functional as equipped with a Smart Alternator Regulator. The original Genie is still working today with no maintenance more complicated than changing oil and air filters.

Cautions and Warnings

Most people have never commissioned an engine, and through the years many have been far too creative in wiring, and plumbing changes to what the manual describes. Failure to follow the instructions in this manual will result in an inoperative and perhaps permanently damaged unit.

The most common problem encountered is lack of air-free fuel to the engine. Diesel engines take just four things to run ...air, fuel, fuel, and fuel. If the Genie engine has air and fuel, it will run at the correct RPM and produce the expected results.

The second most common problem is neglecting to enable current limiting. The engine does not have enough horsepower to drive the alternator at its maximum rating and without regulator current limiting engaged, the engine will either stall, or lope along at a low RPM where the alternator doesn't overload the available engine power.

Please read this manual thoroughly, and adhere to the suggestions provided.


Do not operate the Genie without a belt guard!

NOTE: The Genie is not equipped with a belt guard. Never work around the Genie when it is operating. Do not mount the Genie such that children or adults can come into contact with the Genie when it is running. After the Genie is installed, and before operation, provide a belt guard that will protect all persons from harm.


Do not share an intake thru-hull with another engine will most likely flood the Genie through the water line when the other engine is running. This has happened to people who have ignored this warning. Under all circumstances flooded engines void the warranty.


Do not overfill the crankcase with oil. You may just get an oily bilge when the excess blows out of the vent tube, or the vent tube may not be able to pass enough to prevent crankcase overpressure.


Do not use pure antifreeze in the heat exchanger. Not only is pure antifreeze a poor carrier of heat, but it also leaks through petcocks and gaskets. Use only a 50:50 mix of antifreeze and water.


If the engine is not mounted 24 inches above the waterline, use a siphon-break between the heat exchanger and the water injection port into the exhaust.


If any portion of the exhaust system is below the waterline, use a waterlift muffler. Mount it at least one foot below the exhaust outlet from the engine.


Do not overcool the engine. Overcooling will result in carbon build up and loss of power.


Do not adjust the current higher than what the engine can provide without struggling. A diesel will emit black smoke when it is overloaded. Always turn the current adjustment down about 15-25% from the black smoke point.


Always let the engine warm up a little before turning on the regulator. When the batteries are low, the alternator will produce full current, which makes the engine work hard.


Do not adjust the throttle linkage so that the throttle solenoid cannot fully pull the plunger into the coil. The solenoid will burn out in a few seconds if this happens.

NOTE: This warning does not apply to units equipped with a fuel solenoid valve instead of the throttle solenoid. Units equipped with the fuel solenoid valve take 10-20 seconds to wind to a stop.

Model Designations

This manual covers four Genie variants.

Model Number Voltage Amperage Cylinders
G12-150 12 150 1
G24-75 24 75 1
G12-280 12 280 2
G24-175 24 175 2

Fuel System

The Genie must be fed from a gravity tank, or an electric fuel pump. Note: Do not use a fuel pump that exceeds 10 PSI. A fuel return line is required. It is often possible to share the electric pump with the main engine, and almost always you can T the return line with that of the main engine. The return line fitting is located at the injector.

No fuel filters are supplied with the Genie. A filter is required, however. If you are not using the filters for the main engine to supply fuel to the Genie, you must mount a separate fuel filter. A filter and water separator unit is recommended.

Make sure that a gravity tank is properly vented. That is, no loops in the vent line where fuel can accumulate and block the vent line. What works as a gravity feed for a main engine may not work for the Genie. Whereas the main engine may be able to create enough suction to clear vent lines with flooded loops, the injector pump on the Genie is not able to do so.

Cooling System

The Genie uses a marine heat exchanger to remove heat from the engine, or in the case of remote sites, a radiator with an electric fan.. A salt water pump is supplied with the marine Genie, and the electric fan with landbased units. The pump can be mounted above the cooling water intake. Output from the pump goes to the heat exchanger. Water from the heat exchanger is fed into the exhaust to cool it permitting exhaust hose to be used. The hose between the heat exchanger and the exhaust must be plumbed during installation.

Note that if the unit is to be operated below the waterline, the hose from the heat exchanger to the muffler will need to be plumbed so that a siphon break can be mounted 2-3 feet above the waterline.

A water screen is required. The Genie pumps up to 5 gallons per minute of water, so use an appropriate water screen.

The engine is designed to run at about 190-210$^\circ$ F, ($ 88-105^\circ$ C). The water pump can be restricted if the salt water is too cold to allow the engine to reach temperature. If the engine runs too cool, there will be a buildup of carbon. The cylinder head should be running at about 230-250$^\circ$ F.

The marine heat exchanger should be filled with a solution of water and antifreeze, mixed 50:50. Do not pour antifreeze directly into the exchanger ...always pre-mix the antifreeze and water before pouring into the heat exchanger.

Make sure there is no air in the coolant system. Air in the coolant will allow operation up to a certain point and then rapidly overheat.

In keel cooled installations an expansion tank is required which is higher than the engine. The expansion tank must be able to withstand the typical pressure of the coolant system, 15-20 PSI.

Installations using the radiator must ensure that the radiator fill cap is higher than the engine coolant plumbing.

Exhaust System

Depending on where the Genie is mounted, and whether the exhaust is above or below the point of water injection into the exhaust, a water lift muffler and perhaps a siphon break will be required.

If the Genie is well above the water line, then it is possible to do without a water lift muffler. Just be sure that all of the exhaust hose is below the point where water is fed into the exhaust, so that no backflow into the dry muffler is possible.

If the engine is above the water line, but some part of the exhaust is higher than the point where water is fed into the exhaust, a water lift muffler is required.

NOTE: A siphon break device is necessary if the engine is below the water line. The siphon break should be mounted at least 24 inches above the water line ...more if mounted off the boat's centerline.

NOTE: Any time a water lift muffler is used, engine cranking must be limited to avoid flooding the engine. Since engine exhaust is necessary to pump the cooling water overboard, sustained cranking when the engine doesn't start can flood the engine. If the engine doesn't start after 20 seconds of cranking, disconnect the water pump electrical feed until the engine is running. Don't forget to re-connect the water pump once the engine runs.

A common problem with generators on small sail boats is flooding of the engine via the exhaust. The exhaust should be equipped with a shutoff valve so that the engine will not take on water in heavy weather.

NOTE: It is imperative to insulate the dry exhaust muffler if the Genie is to be mounted in a small compartment. Fiberglass tape can be used to reduce exhaust heat from the manifold.

Electrical System

The electrical system includes an electric starter, as well as the high output alternator. A glow plug(s) is also present on the engine. The glow plug, fuel solenoid and starter motor all operate from 12-volts, even on 24-volt models. A DC-DC converter can be used from the 24-volt supply to generate 12-volts to maintain a cranking battery. A small 12V alternator is provided on the G-280 and G-175 units.

The standard Genie is started electrically and stopped when its fuel solenoid is de-activated.

If the engine loses oil pressure, or water temperature is excessive, then the fuel solenoid is released and the engine will stop. The red LED on the Run Controller illuminates when there is low oil pressure or high water temperature. Once the engine has been started, the LED will extinguish when oil pressure rises.

Note: Cranking the engine overrides the fact that oil pressure is low. Typically the engine should be cranked long enough to get oil pressure.

Mounting the Genie

The Genie is equipped with four vibration dampening feet. The feet should be attached securely to a mounting floor. The mounting feet are failsafe, that is, they will not separate even if the rubber pads fail.

Plumbing the Marine Exhaust

After the Genie is securely fastened to the floor, the exhaust can be plumbed. If no water lift muffler is used, simply attach the exhaust hose to an exhaust thru-hull fitting. Be sure that all of the exhaust is below the point that water is injected into the exhaust line. Secure the exhaust hose to the dry muffler with two hose clamps.

If a water lift muffler is used, chose an appropriate location for it as close to the Genie as possible, and secure it to the floor. Exhaust hose can now be run from the Genie to the water lift muffler, and from the muffler to a proper thru hull fitting. The exhaust hose should be run as high as possible before it exits the hull so that sea water can not back flood the engine.

Exhaust hoses for the Genie are 1.5 inches, inner diameter. The exhaust thru-hull fitting should be 3-4 inches above the water line. A valve to protect the exhaust from flooding in heavy weather is suggested.

Plumbing the Marine Cooling Water

To plumb the cooling water, a separate thru-hull intake is required. A sea strainer is also necessary. If the Genie is mounted in a planing hull, be sure that the intake is underwater, even when planing.

Water hose size for the Genie is 1/2 inch. Connect the thru-hull to the sea strainer, and the strainer to the water pump. We recommend the use of two hose clamps on each connection. Hose clamps should be made from all stainless steel.

If the Genie is not mounted at least 24 inches above the water line, a siphon break is required between the heat exchanger and the exhaust. The siphon break should be mounted well above the water line.

Plumbing the Fuel System

The engine must be connected to a fuel source with positive pressure. As mentioned, a gravity tank or a fuel pump is necessary.

Fuel to the engine connects to the fitting on the fuel solenoid. A fuel return line must be connected to the fuel tank. The return fitting is located at the injector nozzle.

Electrical Wiring

Wires are required on the starter and the alternator.

The starter must be wired to a 12-volt battery for starting. It can be a separate battery, or the prime battery that the Genie charges. The starting wire should be a #8 gauge. The starter and throttle solenoid requires 12-Volt power. The main alternator can be 12, 24 Volts.

The positive output of the alternator must be connected to the battery that is being charged.

The negative output of the alternator must be connected to the negative distribution point for both the Genie starter battery and the battery being charged by the alternator (12/24-Volt).

Operating the Genie

The Genie is typically shipped without engine coolant or oil. Be sure to add coolant and oil before operating the engine.

Before operating the Genie, be sure that no obstructions are present that can interfere with belts and pulleys. Check the level of crankcase oil, and engine coolant. Open the sea water petcock for the Genie.

Before each use of the Genie, it is good practice to observe that there is coolant in the heat exchanger, and oil in the crankcase. For oil recommendations, refer to the Kubota manual. (For our own diesel engines we use Delo 400 15-40W from Chevron, which meets or exceeds warranty requirements of many U.S. made diesels.) After the first 1000 hours of operation, synthetic oil may be used to extend drain intervals.

Diesel Fuel

In many parts of the world, diesel fuel has a lower cetane rating than U.S. fuels. Even in the U.S. for our own diesels we use an additive regularly, and suggest that fuel be treated for the Genie with a diesel additive. These additives are extra refined oils that enable complete combustion and help to keep the engine injector clean. Some users report using a high grade two-cycle oil as an additive for low sulphur fuels typical in South America. Excessive smoking is often due to poor fuels, an overload on the engine, or insufficient fuel reaching the injectors.

Adjusting Engine RPM

NOTE: Units manufactured after September 28, 2004 no longer use a throttle solenoid. Instead a fuel shutoff solenoid valve is used. To adjust RPM loosen the two nuts on the top of the throttle lever so that it can be moved. After changing RPM to the desired value, re-tighten the two nuts.

Alternator Current Limit

Alternator current limit is set on the SARV3. See that manual for specific instructions.

The engine produces black smoke when it is overloaded. The engine works hardest when current is high, and voltage is at the absorption point ...about 14.4/28.8 Volts. To place the engine under load, deeply discharge the battery and then begin charging. Adjust the current limit, to less than rated Amps. As the voltage rises, and before current through the battery declines, adjust the limit so that the engine is not producing black smoke. Final current adjustment should be 15-25% below the black smoke amperage.

Engine Troubleshooting

The most common cause of failure to start is lack of fuel, which can be caused by air in the lines, an empty tank, a fuel cock that is not on, a clogged fuel line or filter, or a tank which is not properly vented.

To bleed the engine, loosen the bleed nut above the fuel intake and allow all the air to escape. This nut takes a 12 mm wrench. After bleeding all the air from the system, the engine will usually start readily. It is possible to crank the engine at a high speed by holding the compression release lever open. After a few seconds drop the release and the engine should start immediately.

Check the throttle solenoid to assure that it fully engages the throttle. Check the air cleaner to verify that sufficient air flow is possible.

Make sure that the engine is not flooded with sea water. Is the exhaust sea cock open?

NOTE: Never spray any chemical into the intake of the engine. This can permanently damage internal parts.

Alternator and Regulator Troubleshooting

Refer to the SARV3 manual for more troubleshooting suggestions.

Installation and Warranty Support

For questions regarding installation, operation, or warranty service contact PowerTap, Inc. who is the authorized warranty service agent for all Ample Power products. Their phone number is 206-789-4743, and their fax is 206-789-9003.

Email support is available from See also the following websites for more troubleshooting suggestions.

Wiring Diagrams







Ample Power products are manufactured by Ample Technology, 2442 NW Market St., #43, Seattle, WA 98107 - USA