Good compression would show about 130 on my gauge.----So you have a bad guage or a motor that needs work.----Pull bypass covers on the 100 PSI cylinders.----Look at pistons / rings.
There is usually a bit of air above the oil.-----It gets blended in with the oil.------The tiny bubbles that make the oil look " milky "------Let that oil sit for a week or so and see what happens.
I have rebuilt numerous crossflow V-4 and V-6 outboards.----I know they suffer from the broken ring syndrome.----It is easy to understand why the upper ring breaks !!
Draw a picture of the top piston ring.-----Now consider what happens to side clearance when.----piston wears.----when ring wears.----when cylinder wears !!!
Have never seen a warning in an owners manual / service manual or label on a portable tank about running out of fuel.----Agreed that common sense has gone and left us..----Folks just rely on their phone to survive I think.
The 74 model 85 would be my choice if that matters to you.----It is a 50 year old motor.-----I would not even try and start a 50 year old motor.----It would come apart for complete inspection.----Top and bottom.
I can not see , feel your motor.----You have to do the testing and inspection.----Guessing and assuming do not work.----This should be a simple fix.---Sorry if my suggestions based on 50+ years experience did not please you.
They are an excellent motor for those who know what they are doing.----Shops do not want them in the door because they often do not guarantee a profit or a happy customer.----No different than any other old motor.
Sounds like it might be running on 1 cylinder.------In reverse there is exhaust in the water and less load on the prop.-----Post compression values and check spark.
