1986 Yamaha 115p Oil overfow

[PAboater1963]

Hi Everyone

I have read some threads on this overflow issue and I was wondering is there a way to test the Oil sensor. My oil tank fills past the upper fill mark after running the engine for a few hours. The oil reaches the top and flows into the air intake via a small air tube that is connected to the oil tank. The oil also spills out from a very small vent opening near the top of the oil tank. I replaced the control unit below the oil tank from the advice of a marine mechanic . I thought this corrected the proper oil input to the oil tank but still overfilling. The oil sensor is easy to replace but for $250 I would love to hear any advice before spending that kind of money on a hunch . This engine runs great and I hope someone might have past experience with this overflow.

Thanks, Ed Iversen

 

[multimech]

Re: 1986 Yamaha 115p Oil overfow

You have switches in the remote oil tank on the engine that tell the transfer pump in the boat oil tank to start and stop transfer. Your problem is that the switches in the remote oil tank are not communicating with the boat oil tank. Reasons: The oil sending unit in the remote tank is not working. The wiring is not connected correctly. Look for corroded, broken connections. The oil tank sending unit is improperly installed in the remote tank. There is a little nipple that goes into the tank. The floats for the switches are stuck.

Just post again if you need more help or have questions.

 

[eggage1]

Re: 1986 Yamaha 115p Oil overfow

I had the same problem on a 1987 225. I replaced the float assembly in the main tank(engine) and the problem cleared up for the most part. It still continues to pump sometimes after trailering with the motor tilted up but never after that and it used to pump all the time. I'm thinking that the float hangs up after being in the tilt position. Make sure your oil tanks are free of sludge that would gum up the works. My old float checked out good electrically but I had a ton of gum and sludge due to the fact that the boat hadn't been used. If my problem persists I will probably change the control unit over the winter. I know its a rambling reply, sorry.

 

[eggage1]

Re: 1986 Yamaha 115p Oil overfow

Sorry again. I never answered your question.
Disconnect the float at the plug. With an ohmmeter check for continuity on the plug going to the float from the black(ground) to the following wires.
White - float at the top - shut off command
Brown - float from 1/4 way up to top - fill command
Red - Not sure but I think it's the alarm command - float from bottom to 1/4 way up.

The control box takes these inputs and then controls the power to the pump.

Mike

 

[Bamaman1]

Re: 1986 Yamaha 115p Oil overfow

I had the same problem years ago. You would start as said previously by testing the floats. The float in the external oil tank may actually be the same float in the little oil tank. If the floats check out fine, your problem will be the oil control module with the switch.

The oil module replacement the only problem I have experienced in 27 years of great use--other than dirty carbs. The engines are bulletproof.

Thankfully the actual oil injection system is mechanical and very reliable.