oil runs into motor from engine tank

[gilmour69]

The oil in the engine tank is draining into the motor carburetors when the foot is down and if I raise the foot all the way up, then it is draining into the the front of the motor where the front latch is. Any idea what is going on? The remote tank is just 2 years old.

[jb123]

what motor ?
have you checked to see if pump runs constantly?

[gilmour69]

It is a 1986 150 hp. No, the pump is off. It drains all the oil out of the engine tank after about 5 days sitting idle. Then when I turn the key on, the alarm comes on and the pump fills the engine tank back up. Problem is motor smokes real bad burning all the oil out of the motor if you leave foot down, if foot is up, then oil runs out of motor into the water. Seems like it is gravity flowing from the engine oil tank thru the oil pump and into the carbs.

[jb123]

86 has the control unit, do you disconnect batt when not in use?
could be check valves and/or bad seal on pump but wait for a more exp tech to answer

[gilmour69]

With the key off, there is no power to the pump, so no need to disconnect the battery.

[rwwillhunt]

I had the same problem on my 1986 115. In my case the remote tank was located at a higher level then the motor tank. I lowered the remote tank and it stopped the oil draining issue. If your remote tank is higher it may be your solution. If not it would not apply. There are check valves that is supposed to not let this happen. They may have gone bad also. Hope this helps.

[rodbolt17]

if that is the original kien oil pump on the engine then it will have 6 nipples pointed straight up.
most likly one of the check valves below the nipples failed.
if one does then not oinly will gravity drain the engine tank into the intake it will allow that cyl to NOT get oil when running.
crankcase pulses will be transmitted to the oil line.
if the valve failed you can dissasemble the pump and remove all 6 and replace them with the mikuni pump style inline check valves or buy the mikuni pump replacement kit.
the kien pump and parts are and have been NLA for a long long time.
on the oil control module, the original design can and will turn the the transfer pump on if the battery hits about 9 v or lower.
it will then stay on and empty the remote tank.
replacement designs since about 2000 have rewired internal circuitry.