[THEFERMANATOR]

MANUAL OVERRIDE

As long as theres sufficient oil in the remote tank, it can be manually transferred to the main reservoir by pressing the momentary switch to bypass the oil-control unit. The toggle switch turns the pump on for as long as it is held in position; the upper float switch (SW 1) will not turn it off. This allows you to refill the main tank and continue with normal engine operation as long as the float remains above the lower switch (SW 3).

When additional oil is added to the boats remote tank, the float rises above SW B, which allows the controller to turn off the yellow warning LCD. If the outboard is running, the electric pump begins to transfer oil to the engine until the main tanks full switch (SW 1) shuts it off.
Depending on your outboards model year, various methods are used to prevent oil from transferring when the outboard is tilted up. On models with a separate oil-control module, an internal mercury switch will not allow the electric pump to energize if the outboard is tilted above 30 degrees. The trim sender senses the tilt angle to prevent the oil transfer on V-6s from 1990 through 1995. Starting in 1996, new electronics in the controller unit keep the pump from operating if the engine is not running. Do not forget to check these items when troubleshooting a "no oil transfer" situation.

SYMPTOMS TO WATCH FOR

Common symptoms of trouble include a lack of oil transfer, overfilling of the main tank, and oil leaks while the outboard is tilted. Most of the time, these problems are due to operator error and are not the components fault.

Non-transfer of oil to the engine-mounted main tank can be as simple a problem as a neglected filter. Moisture gets into the remote tank from spray, rain, condensation, or from being located in the bilge where it can be splashed or submerged. The water forms a sticky emulsion in the bottom of the tank and plugs up the fine screen in the filter element.

An overflowing main tank sometimes results from someone twisting or incorrectly installing the rubber cap on the float assembly and screen element. The tubular screen has an offset nipple that fits into the bottom oil-outlet going to the metering pump, and can bind the float if moved out of place. The arrow marks on the cap and tank should be aligned.

Leaving the key on by mistake can also cause overflow problems. As the battery run drops below 9.5 volts, the oil-controller electronics go off line, and a ground path is formed which starts the electric pump turning very slowly. Eventually, the main oil tank overfills and spews excess oil out a vent tube into the air silencer box.

While the outboard is tilted, a leaking rubber cap on the main tank can result from improper assembly or from twisting out of place. A plastic tie-wrap snugged around the rubber lip usually cures the leak. The clear sight tube on the bottom of the tank can become brittle with age, and oil may seep between it and the nipple. Replace the tube if it feels stiff, and secure it with a tie-wrap.

TROUBLESHOOTING TIPS

Since the electric oil pump and each switch have voltage going to them at all times, troubleshooting is fairly simple. The electric pump turns on when the ground circuit is complete, and each switch (when activated) completes a circuit. The oil-controller cannot be tested, though and can be considered faulty only through a process of elimination.

When no oil transfer occurs, lift the toggle bypass switch to see if the pump runs and starts to fill the main tank. If it does, either the tank's float assembly is inoperative or the oil-controller is faulty. To check the float assembly, disconnect its wiring plug and ground out the brown (on early engines) or the blue-green wire on the wiring harness side. If the pump and wiring are in good condition, the pump should stay on. Grounding the white (on early engines) or blue-white wire will turn the pump off.

In cases where the pump does not operate or runs without delivering oil, remove the boats remote tank and inspect for corrosion, bad wiring or a plugged filter. You can test the pump by using jumper wires to put 12 volts directly to it. The brown wire is positive and the blue is negative.
Overflowing can result from several factors. If the pump continues to run and the oil level rises above the upper line on the tank, disconnect the wiring and ground out the white (on early engines) or blue-white wire. The pump will stop unless the oil-controller module is bad or there is a grounded blue wire in the harness somewhere between the pump and controller.

TESTING THE FLOAT SWITCH

An ohmmeter can be used to check the switches inside the main tanks float assembly. Carefully remove the unit, making sure the black foam sealing washer stays with the tubular filter element. If it remains in the tank, the seal can be forced into the feed hose going to the engine-driven metering pump which could block the flow of oil.
Hook up the negative lead to the black ground wire, and the positive lead to each other wire in turn. When you move the float, the ohmmeter should show that each switch "closes" when the float passes by. If any switches are defective, the assembly must be replaced. Be sure to install a new foam sealing washer every time the assembly is reinstalled.

Follow the service manual procedure when testing the remote tank's float switch. It is normally closed, and opens when activated by the float. Early models have electronics inside the assembly and require different test methods than later models containing the circuitry in the oil-controller.

Yamaha's Precision Blend oil-transfer system is very reliable, but as an outboard ages, problems may develop. Fortunately, it is a relatively easy system to troubleshoot with ordinary tools and an ohmmeter. Armed with this article and a service manual, you can enjoy the smug satisfaction of avoiding expensive shop time should a malfunction ever occur.