find my oil injection pump please?

[tbrownarcher]

We disconnected the oil injection pump and went to mixing the oil in our "Mercury Black Max XR2 1988 engine". We don't remember where the tubes connected to the engine nor can we locate anything that looks like an oil injection pump.

We did this when we bought it used because we didn't know whether it worked or not. Since then we have been told that the injection varies as the rpm's change. So mixing the oil @ a ratio of 50 to 1 is not the best thing to do. The motor fowls the plugs horridly so we want to reconnect the pump and see what we get but we can't find the pump. Is the pump internal or something ??? We need a picture if anyone has one. Thanks,
Nate

 

[444]

Re: find my oil injection pump please?

If you're fouling plugs, I don't think the oil mixing is causing the problem unless you are mixing it MUCH richer than 50:1. The older black max's like my 81 175 did not have that oil injection system. And it runs just fine.

I think on yours the oil pump is mounted to the engine block. The pump is spun by a little driveshaft that goes inside the engine. And I *think* here should have been a linkage from the carb to the oil pump to ramp up oil flow based on throttle position.

 

[Maxz695]

Re: find my oil injection pump please?

View attachment 94279 My ebay item oil injection pump

 

[j_martin]

Re: find my oil injection pump please?

Oil injection pump mounts on the crankcase, high, port side, facing forward at 10:30 position. It is driven by a plastic gear on the crank, visible through the mounting hole, and by shaft and gear that engages that plastic gear. At the pump end, the shaft is held by a composite bushing with a magnet and spacer in it to drive the hall effect motion sensor, which mounts in a vertical hole right above the bushing.

There are many other parts involved also. The best bet is to buy everything from someone that has pulled it off their engine. Wait... you pulled it off and can't remember what it looks like. :facepalm:

Excessive smoking is usually caused by mis-firing. That can be caused by low compression, bad plug, switchbox, stator, coil, wires, reeds, carburetors, bleed valves, gaskets, err you get the point.

 

[tbrownarcher]

Re: find my oil injection pump please?

J_Martin. We pulled the tube off and took the oil tank from the boat. We never looked for the pump. I did find it and probably it's toast. Anyhow there is some linkage and another reservoir that we don't have so I do not think we are going to try to use it at all.

We are mixing 50-1 and fowling plugs if we idle it too much which we ARE doing a lot because of the no wake lakes here. We can fix that by pulling the plugs and I have another thread today asking what plug to use. We are running NGK buz8h. I have seen other places it's supposed to be NGK BU8H but need confirmation on that .

Thanks to all that took the time to help

Nate

 

[j_martin]

Re: find my oil injection pump please?

Plug is supposed to be BU8H.

I just put Chris Carson fiberglass reeds in my XR4 to improve idle. Helps a lot.

Basic tune is critical, from compression, to carb setting (float level) to linkage adjustment. If all is as it should be, it should idle fine, just a little smokey.