Oil transfer to reserve tank

[jsr21]

Hi..my 1995 merc 225 is not transfering oil from the main tank to the reserve one on the engine...what exactly moves the oil from one to the other...pressure? thx

 

[HSEMJ]

Re: Oil transfer to reserve tank

The oil is transfered from the tank by pressure, specifically crank case pressure. There is a one way check valve that only allows the positive crankcase pulses to pressurize the remote oil tank.

So does the remote tank pressurize? If not then there could be a cracked hose, or loose hose clamp somewhere on the pressure side.

If there is pressure in the tank the a blockage in the pickup screen in the tank, or in the line. Or you have a crack in the oil feed line, in that case the crack should be easy to find, just fine the mess.

 

[jsr21]

Re: Oil transfer to reserve tank

thx for your reply..I replaced a check valve last year because it would not release the pressure after shut down and would keep pressure in the tank..thus filling my carbs with oil and making for a difficult and smokey start up. Is this the same check valve that feeds pressure to my tank? Thx John

 

[gss036]

Re: Oil transfer to reserve tank

Probably not, not sure. The one way check valve is on the lower starboard side of the block, just follow the hoses. The other is a 2psi check valve,(I have one on order at present, it was leaking oil back into the cowling), the other tank hose plugs into it and then on to the engine tank. There is a short piece of hose that comes out of the bottom(at least on my 89 200 carbed engine)it is to be left open, nothing is connected to it.
Best way to check to see if it is transferring oil is to loosen the cap about one turn and see if oil leaks out.
Like hsmej says, the screen on the bottom of the pickup tube could be clogged. I would run pre-mix until you get it figured out.

 

[HSEMJ]

Re: Oil transfer to reserve tank

I'm not sure which check valve was replaced. To my knowledge there is no check valve that releases pressure from the oil tank when the engine is stoped.
There are only 3 check valves involved in the oil system.

#1 is connected to the crankcase and allows the crankcase pulses to pressurize the oil tank. This valve is located on the starboard side of the block toward the lower front.

#2 is in the oil feed line just alittle back from the oil line connection on the oil reserve tank on the engine, This is a saftey valve, so if the oil feed line becomes pluged, the oil pump won't be starved of oil by vacume building up in the reserve oil tank and line.

#3 is inline between the oil pump and the fuel line. it keeps fuel from being forced up into the oil pump when the primmer bulb is pumped and the fuel system is put under pressure.

But now that I think about it, if this check valve failed it would allow oil to continue to flow in to the fuel system as long as there was pressure in the main tank. It may have been this one that was replaced.

hope this helps

 

[Drydocknomore]

Re: Oil transfer to reserve tank

I have a similar problem with my 2000 Mercury 225 EFI. The oil will not transfer from the remote tank to engine mounted tank. I have twins and have literally swapped everything with no success and all of the swapped parts work fine on the other motor. The bad motor does not seem to build up enough pressure to transfer the oil but the pressure coming out of the port seems the same on both engines. Is there also a check valve on mine that could be sticking. Any help would be appreciated.

Thanks,
Joe

 

[gss036]

Re: Oil transfer to reserve tank

Yes , your engine does have check valves. Check the pick-up screen inside the 3 gal tank. Start your own thread and you will get better response instead of hijacking this old thread.