Re: Oil injection on 1985 150 xr2
Well, you are mistaken. The engine tank normally runs plumb full tight all the time. It is kept full by a few pounds pressure to the boat tank, that forces the oil to the engine tank. On setup, you crack the cap loose and let it run till it overflows, then tighten it down.
The switch in the cap tells the alarm module if the oil starts to go down in level, indicating that it is not getting oil from the boat tank. At that point, you have about 1/2 hour at WOT of oil left in the tank.
It's cracked because it was overtightened. It has to be replaced if you're going to run the oil injection.
The oil alert power on self test produces a series of beeps. If they are not present, the alarm can't be trusted. Usually it's just a bad beeper or alarm circuit wire. The same circuit and sounder is shared with the overtemp switch. (alarm)
Theory in a nutshell. A check valve on the block (lower forward starboard) supplies pressure to the boat tank. Oil flows to the engine tank. There's a valve to allow air to enter if the oil line gets plugged. The pump, driven by the crankshaft, is also connected to the throttle linkage. It pumps approximately 100:1 at idle, and 50:1 at WOT. The oil from the pump T's into the fuel line just before the fuel pump.
The alarm module compares pump rotation to engine operation. Both present or both missing = OK. One missing sounds alarm. Low oil in the engine tank also sounds alarm.
hope it helps
john