[rusdad]

I have a 1984 115 Yamaha and the small lube tank drained into the crank and left hand lower cylinder over night.
How easy is it to disconect the lube system.

[douglloyd]

betcha it smoked like crazy when you started it. Made a hell of a mess too.
Well I would start by replacing the little one way valves
that are in the oil lines you can see them in the parts blow up there not too expensive also you might want to check and make sure the tilt up shut off to the main oil pump is working and the float in the top of the engine tank.
You can disconnect the whole system many threads on that here just do a search.
Get a Yamaha shop manual it is the only way to work on these things.

[rodbolt]

usually it hydrolocks the engine,.
the original 84 oil pump had the check valves built into the pump.
the 4 nipples also pointed up.
a quick easy fix is to use the later style inline check valves.
follow the oil line from the pump to the plastic joint, then replace each joint with the later style check valve and you should be ok.

[parrfive]

It’s most likely the oil pump seal. Yamaha won’t sell just the seal. Buy a new pump and replace it and you should be good for another 20 years.

[yamamarinetech40]

Rodbolt, I remember something on these old engines(never see em here, salt claims almost all by 10 yrs.), about the pump running on due to system having auto shutoff on tilt/trim sender? Something about prior to 1991 maybe? Been so long since PC's class, just can't remember but would like to know.....

[rodbolt]

the v4 from 84 to about 05 used a mercury switch in the oil control module to prevent transfer when tilted,the v6 used the same setup till 1990.
the control modules on the early models had a propensity to initiate a transfer if the battery voltage dropped below about 9V.
means if the key got left on or anything was killing the battery the pump would turn on and drain the remote tank.
from 1990 to 95 the V6 2.6L motors ran the transfer though the trim sender to prohibit oil transfer if the unit was tilted.
the 3.1 and all 3.3 motors required the motor to be running to transfer automatically.
the 2.6L motors from 95 had the same setup as the 3.1L motors.
about 2005 or so the V4 control module and all V replacement module, tapped a signal from the pulser coils to let the module know the engine is running and to allow transfer.
the modules with the green pulser coil wire also have resistor spark plug caps even if they are black and very similar to the non resistor caps.
now I gotta go worky worky or they will shoot me