My brother is getting the low/no oil alert on his '89ish Mariner 45 hp 2 cycle. The oil tank is full, and he's getting oil as there is plenty of blue smoke around.

I'm assuming one of two things - 1) his oil level pickup float is stuck, and we need to break it loose, or 2) the oil pump shaft rotation sensor is bad and needs to be replaced.

Any thoughts? Also, if it is a bad oil pump, anybody convert one of these to pre-mix? With today's synthetics premixed at 60 or 75:1, I bet it would smoke less and use less oil anyway.

The float would be a easier thing to check than the oil pump shaft rotation sensor... I think I'd look into that first...

marine_man

There is no oil pump shaft rotation sensor on that motor. Only 2 things can sound the alarm.
1. Low or no oil.
2. Overheating.

Disconnect either one briefly to find out which one is the cause.

The overheat alarm is a steady beep. The intermittent beep is low/no oil. I am getting an intermittent beep, not a steady beep. There is a float in the tank for oil level, and a sensor with a magnet that senses if the oil pump shaft is rotating. The first is a signal for low oil, and the second is for no oil. Is that not true?

Are you talking about an Auto Blend system or a crank shaft driven pump?

i have the same motor I took off all the injection stuff and mix my gas they are a very good motor but a few mechanics that i talked to said every motor that they seen with any real problems all were traced back to not getting enough oil or none at all if you ruin 4 cylinders it wouldn,t pay to fix . Also they told me that the alarm most of the time will not sound until there is damage which is to late. i also found one mechanic that said that they work good with no problems. I just wont take a chance with my motor'

I also own a 45hp Mariner from '87 (first year with oil injection). I took the fuel injection off and mix my own as well....Runs like a dream! What is your mixing ratio raymondk? I lost my little black book with all my notes in it and I don't have an owner's manual for the engine. Cheers!

I mix a little leaner then 50 to 1 . i am going to try amsoil and to see if is better.

For an outboard using pre-mix (whether designed as a pre-mix engine, or an injection engine with oil injection removed or disabled doesn't matter): 2 oil choices with AMSOIL:
AMSOIL Saber Outboard you can use as lean as 100-1.
AMSOIL HP Injector used as a pre-mix at 50-1

Excellent. Thanks. I've been mixing 50 to 1 with some mercury but I would like to run a bit leaner as well to get rid of any smoke dispersion.