[rooster1]

just purchased a 35 hp 89 model went to check the lower gear oil its black and real thick how do you get it all out ?

[steelespike]

Add kerosene or other thinning agent 10wt oil might work.Crank it up
put it in gear and stir it up a little.Repeat as required.

[rooster1]

dies it smelling bad and black a bad sign?

[HighTrim]

just means it hasnt been changed in a while. You can use the kerosene like stated, or diesel fuel to flush it. Make sure you change the vent and drain screw gaskets as well.Keep an eye out for metal filings on the drain screw, it is magnetic. Good luck